I don't think I have to worry about that since I'm a guy, but yeah... I take my drink everywhere with me... even to the can.
My ex almost had a problem with that... we went to a party with a bunch of dudes she knew (I told her I don't trust them) she thought I was paranoid or jealous. It was scary cuase she'd keep going in and out of consiousness. She'd be slurring real bad one moment, then the next, look up as us (me and this girl Stephanie) and ask "What's wrong?" all serious like. Then the dude who invited her comes up to me and is like "Hey, Allen... you can drop her off at my apartment, I'll make sure nothing happens." I soooo could have decked him right there, but I knew no one there so decided against it. No, she didn't stay at his apartment that night.
Another time (after we broke up), she was hanging out with the same dudes I told her I didn't like and she almost got raped... they slipped her something again. Luckily this other chick that was with her walked in on her and the dude and stopped everything. Get this: my ex tells me... "I don't think I'm going to go over there by myself again"... WHY WOULD YOU GO AGAIN ANYWAY???? Stupid broad...