Prime Toilet Usage Time - pronounced Pee-Tut.
This the moment in time on public transport, especially airplanes, when the toilet is as popular as the curry everyone ate the night before.
Occurs immediately after the seatbelt signs turn off. This is when, after a massive night of drinking, one should occupy the toilet a.s.a.p., and then do his stink. Results vary.
"I just got those fuckers good, I just stank out the whole back cabin during ptut"
"Go man, go! Its P.T.U.T.!!!"