Are you trying it at night? I think in Hints it says you should interact with your friend at night. so 6 to 8 p.m.
Yep, tried tried that as well. I have read somewhere that her roommate shouldn't be in the room, so I was paying attention to that. Thanks for trying to help :) Someone said you might need to be at a certain level of exhibition (he wasn't sure). Do you remember what was your exhibition level at the time?
Since I have started to go into detail I also should mention that I actually got that option only once, long before any party event, but never got it again after that.