How long have they been acquainted with each other? If you just got one of them, I would just leave their cages side by side so they can sniff and chatter through the bars, and slowly let them in a room to play with supervision! When I got my Pippin (male), my Blossom (female) kept mounting him for dominance. He didn't like that very much and they both started fighting. So I kept their cages close together, and then one day got them a NEW cage that neither of them had been in (so they had no reason to be territorial) and we had a few scuffles at first, then they started cuddling and now they're mates and love each other! Now, what I think helped this process was Blossom's Mom, Pikachu. She got right along with Pippin and I think she kind of helped the situation. But I've also heard to use the same dust for each chinchilla... That way they get each other's scent allll over them! Hehe! I hope this helps, and I wish you luck! I know how frustrating it can be!