'LHHH' Moniece Slaughter Gives Ray J's Marriage 2 Years Tops!

So much for true love -- just days after Ray J and Princess Love tied the knot, their 'LHHH' co-star, Moniece Slaughter, is ready to bury their marriage ... and she's got the first shovel full of dirt.

This could be a classic case of sour grapes -- after all, Moniece didn't get an invite to the wedding -- but on her way out of seeing a movie with Milan Christopher ... she claimed Ray's got no shot at being a one woman man.

A little background on this beef ... Moniece hooked up with Ray J before Princess was in the picture, but the fling still caused drama, and the two have been sending shots at each other since.

We'll give Moniece credit for saying ONE nice thing about the couple. Just one.