From the word "for real" used in slang yet not used to confirm a statement but instead, used to denote sarcasm and doubt and said several times in a mocking way.
Dude 1: I just boned a very hot chick
Dude 2: like f'ril? f'ril?...no seriously, f'ril?, hot chick?(raises eyebrow) duuude f'ril?