Katy Perry Last Friday Night(T.G.I.F.) new official music video. Katy turns into a geeky 13 year old high school student with braces and glasses and has named her alter ego Katy Beth Terry. Last Friday Night is a party anthem that features Glee stars Darren Criss, Kevin McHale and YouTube star Rebecca Black. In the video Katy wakes up after a party in bed with the school hunk and her house completely trashed.