Bonded bunnies nipping each other..

Some advice please if possible...

A few months ago we adopted a bonded pair of bunnies from PetSmart. When we got them we were told that they had always been together and that the owner just could not look after them anymore. They had been instore for almost 2 weeks and both were *fixed* and healthy with any jabs they needed.
As far as they knew both were 2 years old.. not much more info on them it is not known if they are from same litter. I know they are lops (and I beleive they are german lops - I will get some pics up later, be nice to have it confirmed).

The Grey (nibbles) is a little larger than the brown (cuddles) making me think he is a little older (I have to be honest I dont trust PetSmart at all), the brown is certainly a lot more curious about things and more active, but they both are fit and healthy.
If I had to say which I thought was dominant I would say Grey as the other seems to follow him about more and the grey receives the most grooming.

They are kept together indoors (they have a pen and cage in back room but are usually free to roam during the day - plenty of room) and once settled in they seemed happy enough. You often see the cuddled up againts each other and when one goes the other follows.

They have been fine untill this last week or so...
Now suddenly im seeing an odd tuft of fur in the cage during the morning change both grey and brown furr.
I have also observed the brown smaller one going nose to nose with the grey and then suddenly nipping the greys nose! The grey returns the nip and this then makes the brown back off and run, most times the grey will persue through the 3 down stairs rooms and keep going untill he gets the brown with a few nips at this point the brown is trying to nip back more in defence, if cornered it truns more to a scuffle.
I have not seen the Grey start this nipping it always is the Brown to nip first.

There has been no blood and apart from the odd fur and scuffle sound you wouldnt think anything is going on.
The really daft bit is befor this they are napping together and I know that afterwards they will be back together again cleaning each other and napping.

Im not sure why they started doing this as they were fine before, I had wondered if perhaps they wernt *fixed* or if perhaps only one was.

Something that just popped into my head was that while they are both litter trained, we did only have 1 try at the start and I originally thought they were getting used to it so left the odd accident behind turned out to be we needed 2 trays as once we added a second the accidents stopped. My thoughts at the time was that one liked the try but didnt like the other using it (territory perhaps).

Any thoughts on why they are nipping each other??
Thanks.

How sure are you that you were given the correct information that they have both been done? You have said one is a boy but I cannot see the sex of the other? Is it a boy too?

Is one of them poorly?

Do you have anymore rabbits that they are smelling?

Hi sry yes both a boys.

After having a quiet day today with them being together and no nipping Ive just seen cuddles (brown) hop past nibbles (grey) and nip him on the nose and run away! There was no need for it Nibble just sort of snoozing there and cuddles nipped him as he passed :shock:

Im starting to think he is doing it as a windup.

There are no other rabbits (sent wise) and both seem in good health.

Also after having a good look around on this website found some pics regarding boy/girl/sex/neutering...
Having a good look about, im sure both boys and not seeing any obvious err bulges and conclude from that both are snipped - did see some rather confusing for want of a better word cuts or slits, 1 either side of nibbles rabbits bits. That I didnt expect? What should I see scar wise if it has been done? by that I mean what exactly goes on I assume a small cut a snip (removal) and a stitch backup?

Unfortunately if they were done I can say when it was which isnt helping.

Thanks again..

Once boys are neutered the empty sacks that contained the testicles shrink so there is no visible scar. The slits you saw were probably scent glands.

It is quite odd behaviour, as you say it sounds like they are winding each other up rather than having a big fight.

Have you changed the routine for when they are out or what areas they have access to? Two boys together are the most likely match to be territorial and a change in territory can trigger aggression as they try to settle who is the boss.

It might help to give them access to a set area and only that area rather than giving them access to different areas depending on the time of day or your routine eg different a the weekend if your working in the week.

My boy Strawberry does this to other buns too. He purposely nips them to prove he is in charge!