Bunny Woes

I'm feeling frustrated because Putter can't seem to get past his occasional aggressiveness with Hopscotch.  Tonight, it wasn't even 30 minutes together, and Putter began his dance of sneaking up on Hopscotch from behind and nipping him.  But then he would circle around and come up to him face to face and lean down to be submissive and let Hopscotch bathe him.  However, Hopscotch seemed less interested in bathing the rabbit who keeps nipping him and I don't blame him.  I feel the love that Hopscotch was so willingly showing is fading.  I have no clue on where to go from here so I may try to reach out to some bunny connoisseurs.  Wish me luck!