I'm not 100% grasping marriages/melding.
I'll run you through what I understand/think of it so far:
If I have lead, and a matching (trump, for this example) King/Queen, I can lead one of them, say "marriage", and reveal the other. Now, the opponent responds to the lead trick with a Jack and if I win, do I then receive the 20 (or 40) points PLUS 2 points for their Jack? Also upon winning would I put both the King and Queen and their Jack together as a trick and in my pile?
If the above is true (I'm guessing it's not), then that would bring my hand to 1 card smaller than opponent, and that makes no sense to me.
Surely I'm doing some of this wrong, heh. I've tried reading Pagat's rules, and any other sources. The only thing I'm certain about is revealing, must have lead, and also must win a trick anytime during that hand for points to count.