Okay... even I'm grossed out (and turned on) by this french made movie, it's about a murderous man and a woman with serious oral fixation issues, the woman likes to kill her victims by chewing off their lips as they kiss and make love, very bloody, be prepared.
http://www.primewire.ag/watch-216276-Trouble-Every-Day
happnens around 59:00
YOU HAVE BEEN WARNED