Prebonding. I can’t emphasize it enough. After Dutch has been neutered, take 1-2 months to swap them between their enclosures every day. You want to make sure that there’s no aggression when they are in the other buns’ cage. A stuffie is another good idea during prebonding. Give each one a stuffed animal and swap those between them. Some buns are a tad humpy, so you’ll get to see that with a stuffie, also you’ll get to see if they look aggressive or alright with the other bun. Once you’ve prebonded for a least a month and see no aggression when they’re in the opposite’s cage, then you can start short bonding sessions in neutral territory. Start with 10 minute sessions and when they can go 10 minutes without any incidents increase it by 10 minutes each time until you hit 60 minutes. When you hit 60 minutes with no aggression you can start upping the increments to 30-60 minutes longer. And always end a session on a positive or a neutral note. Never end on biting, fur pulling, chasing, or boxing.