Maybe they aren't the ones with the problem.
It seems my social networks are positively swarming with awkward people, shocking numbers of them. I cannot tell you how many times I've had the following sequence of conversations:
Me: Jane wants to come with us, too. Is that okay?
Dick: I dunno. Jane is just so awkward.
Me: Really? Dick, what do you mean?
Dick: You know, she's... awkward.
(later that day)
Me: So I was talking to Dick about who's coming tonight, and--
Harry: Dick's coming?!
Me: Yeah, is that a problem?
Harry: Well, not really, it's just that Dick is so...
Me: What?
Harry: ...he's so awkward.
Me: Oh really.
Man, just say it.
Say it, tell me that you have a hard time with so-and-so because you don't understand him. You don't know how to relate to him.
Explain to me that her entire background is different from yours; you are two very different people.
Say he doesn't communicate in a way that makes sense to you. Say he misreads your body language.
Admit that she's unconventional and you can't predict what she'll do next.
Say he's shy and quiet and seems to be on edge around people he doesn't know.
Tell me she says, out loud, the first thing that comes to her mind and people tend to find it offensive or strange.
Own your feelings, your opinions, your limitations and your discomfort. Go ahead and say you just aren't interested in any of the things he wants to talk about.
But do not, HEAVENS PLEASE do not waste our time by telling people that someone is "awkward".