Ok in order to successfully steal a mare you must post a riddle with the name of the mare in it. So if I wanted to steal a mare named Penatly I would put something like this:
I watch her everyday.
My heart growls in envy.
I was not fast enough.
My Penatly is not being with her.
She will be mine.
He has three moons to answer or the vix is mine.

Only don`t underline the mares name. Anyway the mares stags then has three days to post back no you can`t have her, or whatever. If he doesn`t just say its the fourth day and he post no way jose. Then you still get the fea. If he wants her back then he has to create a riddle and try to steal the fea back and so on.