This is how Mpreg babies are born..

needmoreyaoi:

(This is from a conversation with my friend )

When a seme and a uke love each other very much, they make a very importent desicion. Then, a little fairy comes to their bedroom while they are doing it in the butt, and the fairy puts a small spell on said uke’s tummy and POOF mpreg.

You got it all wrong. Mpreg is kinda based on the concept of seahorses. as you know male seahorses are the ones getting pregnant insted of the females.  So I personally think mpreg is kind of like seahorses.