It’s common enough. It’s often innocent, but not always. I’d say trust your instincts. If you’re not comfortable being one-on-one with the guy, don’t do it. It sounds a little skeevy that he tries that with every woman he knows.
This particular guy is a bit flirtatious, but that’s just his personality.
Going by this thread, I guess I am overreacting, and I should accept his invitations in the future. Or, invitations from any other guy. Shame on my past guy friends for not doing this with me. 
I do it all the time (well, I’m not social, so not all the time, but regularly enough). I’m a girl, and most of my close friends are guys. I also prefer one-on-one interaction to large group interaction. Honestly, I don’t even think about it.
I would clarify most of the points made here a bit more crudely:
If he is a good enough friend that you can tell him that you will never fuck him and are only going to dinner, then yes; go to dinner with him.
If you are less comfortable with him than that, which might be indicated by this post, then continue to decline, and let him know that you will not ever…
I do it all the time.
If I recall correctly, the OP is gay, so presumably this guy would know he’d be barking up the wrong tree.
I think it’s common and I do it often. Like “Angel of the Lord” I don’t really think about it. For the most part (most of my young adult/adult life) I tend to become better friends with men than women. Whether going out to dinner may lead to other activities, depends on many obvious factors.
I don’t know, I’d say you should follow your instincts. If your gut tells you not to go out with this guy, then don’t do it. Nor should you go out with any other guy just because they ask. Why would you?
27-year-old female. Many of my good friends are male, and this has been the case since high school. I frequently go out to dinner with, have over for dinner, or go over for dinner with them, one-on-one. This has happened at various relationship statuses for all of us, including both single, one single, and both involved (with other people). I’ve never seen this as odd. Nor does it make *me *remotely uncomfortable when my boyfriend goes out to dinner with/has over for dinner/goes over for dinner with his various female friends one-on-one. In fact, a boyfriend getting weird about me spending time with my male friends would be an absolute relationship deal-breaker for me.
That said, the point is about what *you *are comfortable with. And if *you *are not comfortable eating a meal with a man you’re not dating, that’s your prerogative, and your friend should respect that.
That’s OK. I have no problem with that! My life is obviously not your life, and I’m not in that position.
Because men and women who are in relationships shouldn’t place themselves in situations where they can develop genuine feelings for members of the opposite sex. Regular (or semi-regular) one-on-one dinners can allow you to form an intimate relationship with somebody. That’s why their used for real dates.
Call me old-fashioned, but I don’t think it’s possible to develop genuine feelings for a member of the opposite sex (or whichever sex you are attracted to) unless you nurture a deep and meaningful relationship with them. I’m a guy, and I can look at woman and find them physically attractive, I can talk to women and find they have attractive personalities, I can watch the way some women conduct themselves and be attracted to their values. I can even think to myself that if I was single, this might be a person I would ask out to dinner.
But to actually have intimate, romantic, personal feelings for someone, that takes invested emotional energy. That kind of relationship has to be nurtured. I shake my head every time I hear someone who has either cheated, or strayed, or been “torn” between lovers complain about how they “couldn’t help it” because they “just happened to fall in love with someone else. It was never intended, it just happened”. Sure, you may not have intended it, but you took no steps to prevent it, in fact you willingly participated in situations that would allow for it.
I’m a 28 year old guy, and I have been with my fiance’ for just over 5 years. So, recently when a female colleague of mine, who I get along with quite well at work, asked if I’d like to spend a day hiking with her, there was never a snowball’s chance in hell that I was going to accept. I get along well with this girl, and I enjoy her company at work, but a day hiking? Just the two of us? Nah-ah. Maybe if I was single, maybe if she knew my partner and my partner also came along, but no. Not alone. Not just us. And I politely declined.
To those who think it’s perfectly fine to be in a relationship but spend regular one-on-one time with someone else of the opposite sex, I have a question:
If you found yourself developing feelings for this person, would you blame circumstance, or would you blame yourself?
What is the difference between lunch and dinner? It is just the time of day? People have to work during the day. So if it is light out it makes it ok? That is what is confusing me and a lot of people are saying this and not just you so I’m lost here. Two people who have been friends since they were in high school or college have come to the point where they know they were just friends. And dinner is just as acceptable lunch. It is all about when the two parties are free.
If you feel yourself incapable of becoming a close non-sexual friend of someone of the opposite sex, please don’t project that onto other people.
Why does there have to be “blame”? Either you will break up with the person you are seeing so you can date the friend-you-now-have-the-hots-for, or you will just ignore the non-platonic feelings for FYNHTHF (which may include cutting off your relationship with them). Or, you know, become a cheating dickhead, but that’s irrelevant, since cheating dickheads will cheat regardless.
Being in a relationship doesn’t mean you magically stop being attracted to everyone else for the rest of your life. It just means that, assuming that the relationship is monogomous, you’ve agreed not to engage in certain activities with other people without your SO’s approval. Maybe you’ll develop an attraction for someone else but decide that you like your SO more and honor that commitment; maybe you’ll develop an attraction for someone else and realize that you really didn’t care as much for your SO as you thought you did, in which case it’s not fair to either of you to stay in that relationship.
IMO, if your relationship is so fragile that you can’t become friends with people of the gender you’re attracted to for fear of cheating on your SO, your relationship wasn’t that strong to begin with.
Dinner is generally a more formal activity than lunch. The latter is seen as a more casual meal.
Been there, done that. Backed out of the friendship for that reason.
You see? It CAN be done!
By not taking your cues on adult behavior from Nora Ephron films. It is entirely appropriate for mature persons of the human species to have one-on-one dinners with members of either sex as an entirely platonic proposition. I not only do so on a regular basis, but even go on vacation with female friends, which is honestly more free of drama than going on vacation with a girlfriend or wife. (Or, at least I’m free to ignore the drama with minimal consequences.)
It is not, however, appropriate to pretend to be someone else to a friend on a dating site while driving her store out of business, or stalking a man that you heard once on a radio talk show across country while dismissing your fiance due to a minor problem with post-nasal drip. As I said, don’t use facile romantic comedy plots as a guide for how to live your life.
Stranger
This is where I was going to make a joke, but the only romcom that comes to mind is The Truth about Cats and Dogs, and the only thing I remember from it is phone sex, without even any context for it. 
Yeah, for me it isn’t particularly. Often a bigger meal, sometimes more elaborate, but only on special occasions more formal. This may ( almost certainly ) stems from my upbringing in which by my mid-teens genuine family meals were virtually confined to the holidays - you’d come home and either make something yourself or some parental unit prepared something ( generally single item, like a crock-potted stew ) and you’d eat it catch as catch can.
Almost 43 yr old male and I don’t really give a second thought to eating dinner or lunch with platonic female friends, married or single.
I go for dinner with women all the time, as friends. However, it’s also true to say that if I see a man and woman out alone, I tend to assume they’re a couple.
I know, there’s some hypocracy there, I only became aware of it recently.
But anyway for dinner, it depends what kind of dinner we mean. If I’ve reserved a table at the most expensive restaurant in town, and we’re buying bottles of wine and all that…it’s too much of a dating environment. Even if I hadn’t intended it as a date, it would start to feel like one.
OTOH spontaneously deciding to go to a more low-key restaurant (and I don’t mean a cheap chain restaurant), and split the bill or whatever…sure, I do that all the time.
I go to dinner with my best male friend all the time. We’re both tall w/ dark hair & about the same level of attractiveness so I always joke that the servers/staff probably think we are together, and when we’re in a bar I worry about cockblocking him. We are the very best of friends so it’s never awkward. The OP sounds like perhaps she doesn’t know the guy friend in question very well. (Not hating, just making an observation.) I wouldn’t think twice about going to dinner with my best male friend, and I am friends with two of his exes.
I’m not saying that dinner is necessarily more formal–simply that it has those connotations for some people. Also, if there is going to be a formal meal, it’s usually dinner. When was the last time you got dressed up all fancy for lunch? If anything, lunches are for business.