Fireproof
Kirk Cameron was notorious in Hollywood for never wanting to do a kissing scene. He took a vow to his wife that he would never kiss another woman again and has stuck to his word. For Fireproof, the filmmakers had to come up with a solution to this problem. They actually disguised Cameron's wife as Erin Bethea's character for the kiss. So, he did kiss the character, but it was actually his wife!
How I Met Your Mother
Despite being an onscreen couple for years, Alyson Hannigan could not stand kissing Jason Segel. Apparently, Hannigan hated Segel’s breath because he was smoking cigs on the daily. At one point, she refused to kiss him until he quit. Segel initially had to pay Hannigan $10 for every cigarette he had, but eventually just quit!