Top Definition
The act of having sex with your flatmate, even though you know this may be inadvisable given that you have to live together afterwards.
"I walked into Rachael's room and she was in bed with John! They totally committed flatcest last night!"
by possessed June 23, 2007
5 Words related to flatcest

Free Daily Email

Type your email address below to get our free Urban Word of the Day every morning!

Emails are sent from We'll never spam you.