I shouldn't even share this, but when I lived with my husband, before we were dating, he often wore sweatpants, thinking he was hiding it. In fact, the opposite was true. Sweatpants do NOT hide it at all.
Much obliged for the info. I wish I could have just uploaded it, though. But perhaps I'd need the spoiler tag, since you can't unsee the image. Maybe it's for the best to add the extra step.
Not really a lady, but what the hell: it's difficult to say without knowing the people involved (esp. the girl and your gf and their relationship), but some girls also step on each other's toes (some sort of power struggles) and gauge what they can't and can do with each others' boyfriends. A female friend of mine did something like that at the onset of KaTrian's and my relationship; tried bossing me around (like telling me to fetch her a drink etc) and stuff, but it was pretty much poking the ice with Kat, seeing how she reacted to that. Once I realized what she was doing (with a subtle hint from Kat as I can be a bit too gullible when it comes to the ladies) and stopped, she backed off (apparently approving Kat's way of handling it) and now we're all good friends. However, if she had sat in my lap or shoved her ass in my crotch, it would've crossed a line, even more so nowadays; she knows both of us and what level of contact we're comfortable with. I'd imagine the girl in question knows your gf well enough to know what her limits are, so if she knows your gf would be fine with it, she might have been trying to see if you were game as well. If she knows your gf wouldn't appreciate it (which is my hunch since it sounds like she did all that stuff pretty covertly), it implies she's trying to step on her toes for whatever reason, not something a friend would do. If I were you, I'd just ask the gf, tell her what happened, 'cause that way you'll get a better picture of what was going on.
I think there might be a clue in what was happening at the time. You were all getting your picture taken, probably to appear on Facebook or some other social medium. Some folks like having party pictures of themselves looking quite raunchy and debauched posted on these sites. Makes them look like they're the life and soul, etc. I'd say if she doesn't ever do this to you in any other setting, I'd just let it go.