A survey of sex therapists concluded the optimal amount of time for sexual intercourse was 3 to 13 minutes. The findings, to be published in the May issue of the Journal of Sexual Medicine, strike at the notion that endurance is the key to a great sex life.
If that sounds like good news to you, don't cheer too loudly. The time does not count foreplay, and the therapists did rate sexual intercourse that lasts from 1 to 2 minutes as "too short." [Source]
Think about it. You can bust a nut at the half and then watch your team in victory. A win for everybody.
Sex takes 3 to 13 minutes, study says [CNN.com]