Going Too Far

I just watched Laurel Canyon again last night, and I forgot how much I liked it. If you haven't seen it it's worth a rent but what is really interesting is the concept. It's about this couple that moves in with the boyfriend's ex hippy mom who has all these boyfriends, sleeps till noon, drinks a lot, etc. The straight laced couple starts to incorporate some of her lifestyles into their relationship so at first you are all "go for it!" Anyway, it started me thinking about trying new things vs. turning things into a big mess.
At what point do you look around and go "this is really not comfortable"? I'm sure we've all been there. I mean, that split second at 4AM when you realize you don't know anyone at this party anymore and you need to go home. Like now.
The whole movie is about thresholds, uptight to experimental to way over the edge. The funny thing is how difficult it is to pinpoint the real moment when things go awry. If it's tough to find in a B movie, good luck finding them for real.