14. Min-sik Choi and Kang Hye-jung in Oldboy (2003)
As its happening, Min-sik Choi's physical connection with younger actress Kang Hye-jung in Oldboy isn't nauseating; in fact, it's a good thing, since Choi's character, Oh Dae-su, just finished a forcible hotel room lockdown for 15 years. The man deserves some action.
The nausea develops, though, once the movie's knockout of a twist rears its ugly narrative head [Spoiler Alert]: Mi-do, the beautiful sushi chef who has taken a liking to Oh Dae-su, is actually his daughter. It's a testament to director/co-writer Park Chan-wook's storytelling abilities that this reveal is even more sickening than watching Oh Dae-su slice his own tongue up as a form of self-induced punishment.