why did she take him to the stripping? was she bi?

I assume she took him there because she was trying to get him to want to get out and do something, not just sit at home, and she thought that might do the trick.

I don't know about passionate desire, but she may have just been enthralled with the woman, impressed. Or maybe it was even desire, but that doesn't make her bi. I think everyone has occasional moments when they're attracted to someone they wouldn't normally be attracted to.

Who knows? The movie doesn't say or imply it at any other time.

A) she took him there to get him turned on so that he would sleep with her. They had been dating for a while and he kept avoiding that, so she thought she would get him so excited that wouldn't avoid it any more.

B) she wasnt looking at the girl with passion - she was smiling because she was sure that her plan to get him excited was working. She might've also been smiling because she was getting another girl to excite him and she thought that meant she could stay lady-like and wait for him to make the first move. It's a good plan, so she might've been smiling just because she was pleased with herself for thinking up the plan.

C) she might've been smiling for another completely different reason. As a film studio executive she probably brings certain clients (like producers, actors, etc) to these kinds of clubs [which would explain why she was so comfortable abt bringing him there] and sees those guys go home all excited - this is probably the first time she thought of using that effect to her advantage. That would make a lot of people smile.