HI guys

My glans is really sensitive when my partner plays with me.  The feelings and sensations are fantastic, don't get me wrong, but I never cum.  I leak, and have sensations ripple through my body (would this be classed as a body orgasm?).  

Anyways, the real crux of the matter is that when I begin intercourse with my wife, it doesn't take long before I've ejaculated and orgasmed.  How come I don't cum when I'm being masturbated?  Is this something I could learn for intercourse?

Many thanks

E