I can last a ridiculously long time, which luckily most people have seemed to like. My sessions usually go for 20 minutes easy, longest I've been is an hour, I could probably go much longer though. Now this all depends on sex, masturbating or blow job.
If it's sex then the above answer is what I was referring to.
If it's masturbation, I have gone 4 hours once, man what a load that was.
If a blow job, depends on the quality, sadly my ex wasn't the best at bjs I never came from her giving me one, in fact our first sexual encounter she ended up blowing me for 2 hours and I still didn't cum in the end.