i've dreamed that i was masturbating, and then came in my sleep. i have no idea if i was actually jerking or not though. i didn't delete anything, because i've got big cojones.
I occasionally experience Lucid Dreaming. This is the state where, although you're dreaming, you are aware that it's a dream & can take control of what it is that you dream about. Needless to say, sexually orientated dreams are the most common subject I lean towards. Unfortunately, even my dreams tend to be realistic in many ways, and when dreaming that I'm having sex, as in real life, I reach the point where I need to bring myself to the brink of a climax via masturbation before I can continue to ejaculate whilst penetrated. However, once again, as in real life, even this sometimes results in an manual climax - and this usually tends to be the point at which I wake up - more often than not with an erect penis in my hand, climaxing within seconds of waking up.