How old before separating?

Hey guys, I remember being told that none neutered male rabbits will fight, so at what age should I separate my friends male and my male rabbit? they are getting along just fine for now, but I don't know when that might change.
Also if I have my rabbit living separately from my friends, would they still be able to meet up and play once they are neutered or would they fight because they don't live with one another?

I'll answer your second question first. Bunnies are either a bonded pair and live together 24/7 or they are not. Bunnies cannot have casual friends or play dates. Such occasional meetings are stressful for the rabbits at best and can cause territorial fighting.

So if they will be housed separately once neutered, then there is no reason to encourage bonding at this point. Anywhere from age 3 to 3 1/2 months until 6 months, those hormones can cause aggression or fighting.

I have to disagree. Rabbits can have fun playing together, even though they aren't bonded. I have different groups of rabbits that aren't housed together or bonded, but I let them play together, based on how well they seem to get along with each other, and they seem happy and have fun playing. This is playtime outside, so they have lots of room to run around. But there are some of my rabbits that I don't let play together cause I know they would fight. So it just depends on the rabbits, on what's going to work out. I will say that with unneutered males, that it can be more challenging cause they tend to be much more hormonal. Just keep an eye on their behavior to one another, and if they seem to start irritating each other, then you may need to stop playtime until they are neutered. But as long as they are getting along and are happy playing with each other,no reason to not let them. Just always keep an eye out for changes in their relationship. Probably best to always supervise playtime, so you can stop anything before it starts.

I would keep an eye on them for now - my girls actually stayed together until their spay dates (at 5 months old) with no fighting; it really depends on the bunnies' personalities and when those darn hormones start kicking in. obviously at the first sign of a fight, they'll have to be separated.

as for the "casual friends" thing... it's iffy at best. definitely *always* supervise their time together since they won't be truly bonded, and I highly recommend having their playdates on "neutral" territory (ie territory that neither one has ever spent time in alone - either neither bunny has been there, or they've ONLY been there together so it smells equally like both of them and they remember playing together in it).

Thanks guys, this is all helpful information!