These people had at least four on set romances with their opposite leads.
#1 - This actress was everywhere in the 90's. She had on set relationships twice with this at the time A list actor who all of you know. She also hooked up with a foreign born former A+ lister and an A list actor who just wanted to watch her undress.
#2 - This A list actor from an acting family hooked up with this three named actress who has a connection to one of the actors in #1. He also hooked up with an actress who starred with the actress in #1 in a movie. Oh, and of course he hooked up with this actress/director and an enemy of the actress/director.
#3 - This former A+ list comic actor had an on set relationship with an actress who was a pretty big deal but was forever scarred from her relationship with the actor and really didn't work much after. Another actress all of you know was making her first movie. She also regretted the relationship. Oh, there was the actress who is now married to a director and an actress who used to drink a lot and was in superhero movies.
#4 - This foreign born A list actress had on set relationships with the A list writer of one of her movies. She also hooked up with the lead in that movie. She has never slept with the co-star everyone thinks she has, but did hook up with an actor in one of the movies in which they starred. That actor is in a current box office bomb. Oh, and she also hooked up with an A list director.