When I was a teen, I read in one of my dad's porn mags, Forum I think, about a technique where you can suppress your ejaculation by pressing firmly on your perineum during orgasm. It stops the vast bulk of my junk escaping, with maybe the odd dribble. I believe it is re absorbed or urinated out. No harmful side effects.
I have used this technique for about 25 years now, mainly when masturbating as it is neat and tidy and saves on tissues. It does not diminish the orgasm at all. I have also used it with previous partners as a means of avoiding unwanted CIM, and it really works for this although I guess you would need a trusting WG....
I just have no idea how commonly this technique is used, so I thought I'd ask you lot. I find it extremely handy and always have done.