It depends. Sometimes I can go weeks....... okay, days without knocking one out, without little or no side-effects. Sometimes, if i've got the time, I can masturbate more than once in a night. I don't know why, because i'm always fucking horny. Even when I lived with my ex-girlfriend, and we were having all kinds of sex multiple times every night I would still masturbate occasionally. I imagine the more you have sex/masturbate, the more you need to. I dunno.


Edit: Man, there's nothing worse than turning out the light, getting in to bed, trying to get to sleep and failing because you need to knock one out. You just know it's gonna be a while before you manage to get some rest.