Male Rabbits humping: Please advise!!

Hello everybody.

I've been looking at lots of threads to do with my problem but I can't find one specific enough so here it is:
I have two male dwarf rabbits who came from the same place and had been raised together since the younger (11 moths)'s birth (the older one is 14 months now). The bigger one is called Ziggy and is a nethie-lionhead cross and the smaller one is a pure nethie. I've had them for 3 weeks +. Up until last night they were wonderful: getting along and preening each other, playing, sharing food well etc.
However, last night the larger one (Ziggy) started humping the smaller one (Moth). After reading up, I quickly found that it was a display of dominance if male rabbits hump. There were lots of warnings of it turning into nipping and fighting so I've separated them. In order to keep them bonded, I let them run around for an hour + together every day and they can be in the same cage when supervised, but as soon as the humping starts, I remove Ziggy and put him in another house.
I know that it's probably neutering will solve this. I went to the vet's yesterday, though, and they said that neither of their testes had descended, so we have to wait another month until we go back. I'm worried that by that time my bunnies will be unbonded.
Is there anything that anyone suggests, and am I doing the right thing? I'm really worried as I want to give them the best lives possible and my parents say that if we can't fix it, we'll have to sell one of them and I could never ever choose let alone do that!! You can see why I'm worried?

Thanks in advance,
Eleanor.

Here are Moth and Ziggy together in a YouTube vid I made of them:

Hello and welcome! You have 2 beautiful rabbits there and you did the right thing in separating them as sooner or later they would have had a massive fight and possibly injured one another. At their age the testicles should have appeared but sometimes rabbits can suck them back in, especially if they feel threatened by another rabbit. It could still be that there will be no testicles on show in a month's time also. You need to make sure your Vet is one who is knowledgeable in rabbits as I think some Vets can suck the testicles out in order to neuter them, but not sure and maybe someone else will be along to confirm that. I guess you will have to keep them separate for now as the smaller bunny will most likely feel threatened by the older one. When they are neutered and time has gone by to allow the hormones to subside, you will be able to try bonding them, but there is no guaantee it will work I'm afraid.

Welcome to the forum :wave:

No advice unfortunately but there's loads of really knowledgeable people on here. Your rabbits are very cute x

[ I can't delete this. :? ]

Hello! Thanks for the advice.
I was hoping if they played together regularly (every day after school) with supervision so they don't get into any fights (I separate them as soon as the grunting and mounting starts) then they'd remain bonded?
Is this a good idea, or is there something I haven't thought of?
With regards to our vet, she is a "small pets vet" specifically, although she didn't mention that? I'll ask her next time I go whether she can do something along those lines.
The little one is actually the bolder of the two, so it's a bit surprising he isn't the one being dominating!
Thanks so much again.

Thanks, yours do too. I'm so lucky! x