Sure, you can phrase anything to make it sound shady. To me it sounds like they were doing normal things that happen at club. They were dancing erotically (which is very common in clubs). Then they went to get a drink (people drink in clubs). Then they went to the bathroom (when people drink they have to use the bathroom).

I get the concerns everyone has about women being taking advantage of, but people also need to realize that women are capable of making their own decisions and sometimes want to have sex with a random guy. It doesn’t sound like OP’s friend falling down or black out drunk and she was enjoying herself. But, OP decided he knew what was best for her instead of letting her (a grown adult capable of making decisions) decide what she wanted to do.