10. True Lies
So, to be fair, this "sex scene" isn’t a sex scene at all, but rather one of intense disrobing. Nonetheless, the experience of seeing Jamie Lee Curtis take it all off (after a few false starts) perform one of the more memorable stripteases in cinematic history for the future governor of California blindsided plenty of families who likely thought they were just settling in for a couple of hours of watching Arnold do more typical, explosion-related Arnold things.
9. Boogie Nights
So, an informed viewer should have been prepared for this one, but the combination of critical acclaim and the presence of Burt Reynolds made it a stronger candidate for parental-approved viewing than you'd think. In terms of the most awkward scene... let's just say there are options: Heather Graham going full-frontal with Marky Mark and Mr. Reynolds, William H. Macy's wife cheating on him with, like, everyone, but the most cringe-inducing would have to be Julianne Moore's first on-camera tryst with Wahlberg, featuring enough dirty talk to make offspring of any age want to cover their ears.