Mounting behaviour ?!

Hey guys, I'm looking for a bit of advice.

I have 2 rabbits 1 female at 1 years old and 1 male at 2 years old. We've had our male for almost 2 years now and our female for almost a year. We managed to bond them and have lived together in harmony for about 9 months now woth no issues. Both are neutered and spayed and have been for some time now however I've noticed over the past few weeks that they both seem to be mounting eachother and this is happening quite often, there is no aggression between them and they both groom each other freely and willingly.

I think it's important to say that they were free roaming however we then decided to put them in an enclosure and they have been in this enclosure for over 2 months now with no issues until now.

Is there something i should be concerned about ? Or is this normal and possibly because of the season ? Or could ot be because of the new enclosure even of they have been staying in it together for a while now ?

Thanks guys !

It could be that Spring is coming which does affect them at times. It is most likely a dominance behaviour so nothing to be worried about.

Spring fever does seem likely, especially as the weather is much milder than usual at the moment. Just keep an eye on them in case one decides they have had enough of the other. It's not usually a problem and will sort itself out.