Manojob has had a few scenes where the guy cums fully 2-3 times from handjobs without stopping/cuts. It's the same guy each time. These are very, very good.
These are the ones I know about with such:
Lexi Diamond (think her second one)- 2 cums (she's hot!)
Jessi Stone - 3 cums
London Keyes - 2 cums (there seems to be a cut away after several minutes between the nuts, shouldn't ruin it)
Kandi Milan - 3 cums
Callie Dee (think her 2nd one)- 2 cums (she's cute)
Isis Mano (her second one) -3 cums
Katie St. Ives - 3 cums
Other scenes:
My Sister's Hot Friend with Bree Olsen - pulls out and cums on her ass then goes back in to cum later on
The Real Workout with Mya Nichole - The guy cums from fucking her pussy then puts it in her ass immediately and continues on to cum again later
The Dick Suckers with Darcy Tyler - She keeps stroking him to two cumshots without stopping
Bella Donna's Cock Pigs with Whitney and Britney Stevens - the guy stokes off twice at end, no cut, full nuts