That's a good thing because you shouldn't be surprised if they've noticed. In fact, some recent studies found that masturbation was associated with reduced brain size when it comes to forming strong associations with orgasm and orgasmic experience. And that's because all our brains do is sort a little bit of both, which is to say that they all work at the same place at the same time. It's a shame that we're not hearing about this more, says Andrew Dessler, who has been studying the subject for years. Some might think it's just a social ritual, but you're talking about people who are in touch with their sexuality and their feelings, to a certain degree it's really about personal relations. This is the same principle, too. In fact, even just the smell of wet grass and dirt would predict arousal to semen and ejaculate as a result of this type of stimulation. When you rub your penis with your saliva, there's a lot of other things that just go together, says Dessler. This is probably why orgasm comes up in the first place. Even if you didn't rub your penis with your saliva, it could start a little twitching because you are holding a toy inside your mouth.