Let me get this straight. Guy asks girl for drinks and something to eat. Girl thinks it’s a great idea but wants to bring another guy with her?
That isn’t a red flag, that’s the clumsiest kiss-off in the history of male-female relations.
There’s no way in hell a woman who was interested in a man would bring another man to a date. Sounds like that’s the woman’s way of saying it’s not a date.
But I’m a guy, what do I know? I do know that I wouldn’t go on a “date” with a woman if another guy was coming along.
Maybe it’s a test to see if he’ll put up with shit like that, in which case he should flee…
Maybe she is one of those clueless people who has to be hit by a 2x4 before she understands she has been asked out on a date with romance in mind. She might just assume that all men just want to be friends.
deb – one of the clueless ones, sigh – 2world
Boy, I feel like I live on another planet or something. All these assumptions about sneaky messages/ cruel put-downs. Fears of date rape. Are we back in the 1950s? I can imagine all kinds of scenarios, especially involving co-workers going out together, that would not make any such assumptions about how this girl feels about this guy. I mean, if she wasn’t interested, she coulda said, Oh, sorry, I have a date already. It could be that she regretting agreeing to go out with the first guy and is agreeing to go out with your friend to get rid of her other date. I mean, imagine if she’d rather be “friends” first and waiting to see if it develops into something more later. Sometimes it’s easier to get to know somebody in a group, at least at first. My one piece of advice would be to NOT confront her about this or what her motives are. She will leave in a cloud of smoke. Just be friendly. Show her if you’re the kind of guy she might like. Let things evolve how they will. If he’s worried about second-guessing what everything means, it sounds like he’s pretty insecure and that’s never a good place to be.
Another vote here for - she’s not interested in a relationship with him.
:Sigh: See, this could be me, just being wholly and completely clueless, along with deb2world. Add to that the fact that I love going out with all my friends together, and I have more than once invited people along to an event that was meant to be just the two of us. Only after all 5 or 10 of us have gone to dinner or whatever have I found out that it was meant to be more intimate.
So if you asked me for drinks and dinner, and I showed up my posse, it doesn’t mean I don’t like you. It just means I don’t know you like me.
Well, since we’re guessing intentions…
I don’t understand why everyone’s saying she’s not bringing her buddy along for a second opinion because her buddy is a guy. Most of my buddies away from work are guys. (They’re also gay, but straight guys are capable of second opinions, too. Maybe. Or maybe not. Scratch that… 
)
Maybe things are moving faster in her head than you think, she’s really into your friend and she wants someone else to validate her opinion?
Who knows? I say he should just go with it and see what happens.
IMHO, even if this isn’t IMHO, she isn’t interested.
If a man I liked asked me to a “Hey, let’s grab a bite”, I would not invite another co-worker.
Maybe it’s just me, but this might be a case of phraseology…
IMHO, adding the “get a bite to eat” at the end of the invitation did not imply a formal date.
Asking “Would you go out to dinner with me?” would imply a request for a formal (as in just the two of them) date.
Would it be too much to just tell her, right to her face, that he meant “go out” as in “Just the two of us”?
I have to side with the possibility that she is interested. Maybe she had already planned a friendly get-together with this other co-worker, and decided to combine the two invites. Or maybe she’s trying to figure out what your friend is hoping to get out of this… there’s plenty of possibilities, and no need to just give up right away.
The only real way to settle this is to have your friend ask her out, in a way that mkaes it obvious that this would be a ‘real date.’ If she turns him down, case closed. If she accepts, then he’s good to go.
We don’t know the timeline involved here, but if there’s a few days left before their “date” I’d suggest this:
Your friend gets back to her: “I’ve been thinking about this. I really wanted just the two of us to go, so we’d get to know each other better.”
Put the ball in her court and be done with it. Whatever her answer is, problem’s solved.
Note: This is completely opposite of what BooksWoods suggests. Well, one of us is on the right track! 
In any case, if I were your friend I wouldn’t go under those circumstances. I’d like a date with this girl, and she brings a male friend along? WTF? Can you imagine the tension surrounding the evening?
Maybe I’m just closed-minded, but no way would I waste a weekend night on that mis-adventure!