P90seX
Sex that is unusually rigorous and physically exhausting, similar to the P90X workouts.
"Looks like I can skip P90X tomorrow, that P90seX was a great workout."
P90sex
Intense, long sexual intercourse that results in sweating and soreness of the muscles just as P90X does.
Girl: "That was great...(breaths)"
Guy: "I know, this P90sex is a great workout, we should do it more often."
Guy: "I know, this P90sex is a great workout, we should do it more often."