Broken bond?

Hi all, you'll have to excuse me if this is a long post but I'm a little worried.
I have two rabbits, a male and female, the male is neutered the female is not. They have been bonded and living together for around 4 years now with no problems, the male can sometimes be a little food aggressive (chases her away so he can have the food first but then lets her eat with him) she also tends to mount him in the spring and summer seasons I'm assuming due to not being spayed.
She grooms him the majority of the time and I have noticed that sometimes when she mounts him, she fur pulls.
That's the background of it all.

A few days ago I noticed my male had a little bit of fur missing from his back between his shoulder blades but honestly thought nothing much of it as I assumed my female had overgroomed, today I decided to have a closer look and noticed he had a little bald patch with the edges being slightly red.
when poking around it he didn't seem in pain and the wound seems clean, before I make a vets appointment I was wondering if any of you knew if it could be fur pulling or something else?
My bunnies seem to be acting a bit more aggressive towards eachother lately and although they haven't fought (the male tends to just chase her away) I'm wondering if they could have broken their bond slightly? Don't get me wrong they still snuggle and do everything together but something seems a little off.
Thanks for any help you can give me and again I apologise for the long post.

Has he had a vaccination recently?

Have you seen her hump him recently? Have you noticed fur around?

Also, is there a particular reason she's not been spayed?

No he's not had a vaccination lately, but yes I have seen her mount him, she does around this time quite frequently, he obviously has no interest in it so moves away but sometimes she can be quite stubborn and holds on tight.
And no there's no particular reason, I probably should of a while ago but they didn't seem to be having any problems until now, perhaps having her spayed would help the situation?

Sounds like maybe she pulled the fur out then, when she was holding on.

It is a sign that her hormones are driving her behaviour and that's likely to be uncomfortable for them both. Plus, getting her spayed will remove the risk of uterine cancers which is very high after the age of.

They can both go to the vets together and likely stay together, unless he worries the wound.

Okay I'm glad to hear that its something that can be easily sorted, I shall sort her out a vets appointment to be spayed then and in the mean time will just watch over the wound, thank you very much