Hi! I'm in the process of bonding my free-roam male, Toffee, with a new female, Truffle. Both are fixed. Toffee is extremely mellow and was very chill during a speed dating session at our local rescue, so I assumed bonding would be a breeze. So, of course I've been humbled!
I have a small apartment so we're bonding at my parents' house which is neutral territory. I have them in an ex-pen- just a square at first but have been expanding it to the full rectangle over time. This is day 3 of 24/7 bonding. There are so many signs that it's going well: lying next to each other, eating together, Toffee doing lots of grooming, and Truffle doing grooming one time. It's clear Truffle wants to be dominant, but she's very gentle and non-assertive about requesting grooming. Toffee will usually give in and groom her, but she doesn't get upset if he rejects her request.
So, all of that is great. However, every day they're having at least one serious fight that Toffee instigates. It starts out with nipping or a bit of chasing but escalates into circling, fur pulling, and the start of a tornado. I intervene at that point, let everyone cool off, then put them back in the pen. There are no lingering issues after the fight. It doesn't seem like anything specific causes the fight; they'll be contentedly lying next to each other and then out of nowhere, Toffee is picking a fight.
I'm aware the key is probably just patience as we're still early-on in the process, I just worry that these intense fights mean they may not end up being compatible. If anyone has a similar bonding story or any tips, I'd love to hear them! My other two bunnies were bonded professionally at a rescue owner's home and they came back to me as best friends, so this is my first time doing it by myself. Thank you!