A person with who you have a strictly sexuall relationchip. Can sometimes also be a "regular" friend.
Almost the same as friends with benefits, but a FF doesn't have to be your friend in any other way than in the bed.
Ex:es often ends up as FuckFriends.
- Nah... But I still see her, thogh.
- Huh? How come?
- Well, you don't have to date to have fun...
- So she's your fuckfriend? Aw! That's soo cool, man!
b) an offensive synonym for a friends with benefits