Sometimes! But I just assume that, unless I'm absolutely certain, then the person don't know. Odds are one or the other forgot anyway, so it doesn't hurt to repeat it. And if the other person does know, they'll probably inform you, and you just play it off as your character being forgetful or something. Works with my characters, at least, though I suppose it may not with yours.
And yes, gotta direct connect to join. It will appear in your history and favourites though, so just gotta do it once. Look
here.