My guess is a near 0% chance of that.
Of course, if the conversation was flirtatious in topic it would be worse, but I would feel uncomfortable if they were having a deep, eye locked conversation they were lost in over their favorite book or about salt water aquariums. At a certain point, conversation subject matter is secondary and really can be an excuse for the interaction.
That’s because you know her.
Let’s face it
when a long term couple goes out together they usually do want to split up and talk to other people. They get enough of each other at home.
A new couple out on a date, totally different thing. They should be hanging all over each other, everybody around them should be rolling their eyes and telling them to get a room. 
Not really but there is a difference.
This is caveman behavior. It’s up to her to let him know that she’s not available at whatever time she seems it appropriate. If she hasn’t done that, it’s not your prerogative to do it for her.
That’s absolutely crazy.
How could you possibly be aware of how someone MIGHT interpret your behavior? Mind reading?
That you went a whole hour being irritated and angry but never once used your words says passive-aggressive to me. You can’t possibly expect someone to notice that you feel uncomfortable because they aren’t focused 100% on YOU until you TELL them that is your expectation.
Five minutes in, you should have joined in the conversation. If you got shut out, then you could have suggested going someplace else. You could have interrupted and changed the subject. You could have done dozens of different things that did not involve sitting there for an hour and seething about it.
Now if you *did *use your words early on in her convo with the other guy and she just ignored you, then I think you are right to be annoyed. That would be disrespectful. But I can’t figure out how you expect her to be aware of how she’d feel about a given action if you haven’t actually said anything. Assuming her convo was actually innocent and she wasn’t just plotting to ditch you at the bar and leave with that guy, I see no reason why she might assume that intently talking to someone for a whole hour would bother you so much.
What caught my attention is the OP skips over the details that would make it easy for me to form an opinionated answer, but has loads of other details - almost as a distraction.
Ok, you met 7 weeks ago, but how long exclusive. And has that been literally, mutually agreed?
How did the two of you pick that bar? And that time?
How did the two of you get to the bar? Expectations can be different if she came with you or on her own to meet you there.
How did Mr # 2 and her strike it up at the bar and how, exactly, did they leave you and go ‘somewhere private’??
I totally understand watching the clock when you’re sitting there waiting for someone. What else do you have to do?!
I don’t understand asking her to leave with you, but I’ll give you the benefit of the doubt as I wasn’t there…
She was being a bit dickish, but you missed a great opportunity to play it cool in response, remaining unruffled and chatting with your friends. Then she might have felt silly and sheepish having missed out. But introducing yourself as The Boyfriend will have come off as hopelessly needy, weak and possessive.
I know this is easily said in hindsight, and I’m not trying to do you down; I have known the feeling.
I think both parties are in the wrong but here’s my take. Yes, she was kind of rude, especially in not recognizing your discomfort when you marked your territory (sorry I see it this way too). That makes her a little self-absorbed. But that’s as far as I’m willing to go when assigning blame. You’re also in the wrong. We all in our heads have what we consider normal behavior, but what we consider normal is extremely personal.
Just from this thread it should be obvious that what some people call reasonable some see as controlling. Here’s the thing, that’s up to the two of you to decide. But this is the kind of conversation you have as you go along not after the fact. On a personal level, replace Dr. Who with Star Trek and I could easily pass an hour with a stranger totally oblivious to non Trekkies in the room.
If the bar was kind of a casual hangout where you both knew people I would be slightly more tolerant of this. Otherwise if you enjoy the sex continue to enjoy it with her but don’t make too much of an emotional investment in her. It would have pissed me off.
Jeez. I couldn’t even get all the way through your OP. Are you 12?
If you don’t trust her, you have no foundation for a relationship with her, and your relationship is doomed. Learn to trust her or break up.
Dating you does not require that she be joined at the hip to you.
She’s allowed to have friends and interests outside of you. In fact, it will make your relationship better, if you don’t interfere with it.
You are not the center of the universe. You are not the center of HER universe, either. Get used to it. If you seriously cannot deal with not being the center of her attention for even an hour, get help. Or you will not be able to function in adult society.
If you can’t treat her as an equal, as an adult, and as someone with both the right and the competency to make her own decisions, this relationship is doomed, and it’s not HER fault that it is.
She is not your property. You don’t get to dictate who she has conversations with, or who she can be friends with. The fact that you are de facto threatened by the gender of her conversational partner – as if she is property that might be “stolen,” as if she has no agency in the matter (see “do you trust her?” above) – is especially appalling and CHILDISH.
Grow up. Or else you have no business attempting adult relationships.
If a long-married couple went to a bar with friends and didn’t spend all that much time together, as one of them found someone really interesting to talk to, that would be totally ordinary and in my mind acceptable. As long as it wasn’t flirtatious in any way.
A couple who really, barely knows each other? Whole different thing. People have widely varying ideas of what is acceptable social behavior as a couple, and she is showing you, at best, that hers are quite different than yours. You are in that delicate phase of a relationship which is full of surprises.
“Mature people” don’t trust each other unconditionally, that’s wishful thinking; mature people talk to each other about the things they do not understand or find troubling in the other person. And then, based on those conversations, they adjust their expectations.
Finding a reasonable middle ground (for example, if she finds herself so involved in another conversation that she guesses you will feel ignored, she could make the effort to either include you or simply check in with you at intervals, even just smiling across the room) entails both of you being willing to bend for the other – because you care about the other’s comfort.
People are rarely very bendy when they feel attacked and misunderstood. So there’s that
What would be your definition of a date?
It seems rude to me to spend that length of time away from one’s date, without even introducing him. She’s the one who went off on her own, so I think courtesy obliges her to make an effort to include him.
That said, introducing himself as the boyfriend makes him sound insecure, and asking her to leave also seems rude to me.
My opinion is that you need to grow up and stop being so clingy-codependent. Is this your first relationship ever?
It’s not like this is your first date and she spent the whole night flirting with the busboy. You’re hanging out at a bar for four hours. You sound super insecure. So does everyone else telling you that this is somehow not a normal thing for people to do. You’re all weirdos.
Also the way that you discuss time in terms of 3.5 and 2.5 hours is weirdly specific. Comes across as creepy and obsessive.
I suggest breaking up with the poor girl so she can date someone who isn’t borderline control freak.
Wow. Who do you hang out with? Trivial? Either you’re projecting your jealousy on everyone else, or you need to spend more time with grown-ups.
For the record, no, it’s not trivial to make “anyone” feel jealous. Most of the people I know are not jealous control freaks – up to and including friendly pecks on the lips to greet close friends. No one in my circle freaks out about that. No one in my circle particularly notices that.
Pro-tip: there is no such thing as “appropriate” jealousy. No relationship can survive without trust.
Why? They were at a bar hanging out with friends, not doing dinner and a movie.
…orrrrr, you could trust her to say no if he pulled any inappropriate shit.
Also it’s clear you don’t trust her.
If you don’t trust her, break up.
Seriously not even the issue, here. If she’s trustworthy, he could hit on her til the cows come home and it won’t matter because she’ll shoot him down. If she’s not trustworthy, why on earth would you want to date her?
Well, that’s progress, at least.
Not even looking at things from a relationship perspective, in terms of etiquette her behavior was rude. A guy leaving his date alone for an hour to talk fantasy football would be equally rude. Then you add in ignoring his friends there as well.
From a relationship perspective - two employed people not living together have a limited amount of time to spend together, assuming they had lives beforehand. She spent a quarter of that limited time re-hashing an old tv show with a stranger, rather than with him or his friends. The message that sends isn’t positive.
For what it’s worth, here’s my take:
I don’t think either of you did anything “wrong.” I also don’t think that she “should’ve known” that her actions would upset you. While it might be obvious to you (as it is to me) that it was rude, some people use a diferent yardstick. I do think you were wise to tell her that it bothered you, and I think she told you a lot about herself when she said that she didn’t see a problem. I suspect that she is somewhat self-centered and may not be as into you as you hope or as you are into her. Just a guess. My greater concern is that, for whatever reason, she appears to be indifferent to your feelings. This is the problem, more than whether she was rude or was sending the wrong impression (more about this later). If she is indifferent to how you feel now, this early in the relationship, I strongly doubt she will become more concerned over time. WhyNot said it best: There are many wonderful people in the world who are not compatible for a long-term relationship. That is my sense here. But, I would give her another chance and see if she learned anything or cares enough to moderate her behavior. If she doesn’t, it very well could be time for you to move on.
As for “sending the wrong impression,” I flinch everytime you say it. For some reason, this feels to me as if you feel like she is making you look bad. Please excuse me if this is not correct. The person who looks bad here is her. The only way you will look bad is if she continues to send out the message that she is NOT in a committed relationship when you think she is, and you continue the relationship and let her treat you that way.
Good luck.