AmnesiA (2001)
A guy gives mouth-to-mouth resuscitation to his twin brother’s girlfriend in front of him, which turns into a make-out session and having sex with his brother’s girlfriend later.
Actors: Eva van der Gucht
Plan Bart (2014)
A chick breaks up with her boyfriend and has sex several times with her ex-boyfriend to impregnate her. She gets pregnant, and after she and her boyfriend get back together, she still kisses her ex-boyfriend.