ok, Blue was neutered in June, and before he was neutered was good about using his potty. and recently he has started spraying all over his cage, and pooping too. Baby is scheduled to get spayed on the 3rd, any clues as to why he might be doing this?

It might actually be because Baby has a different smell to her now that her hormones have arrived. He could be marking against her scent.

OR when Nibbles met him recently, could nibbles have peed somewhere in the area that you haven't discovered yet?

OR...sometimes it because they've had an upset, fright. Say if he sensed an animal coming up to the house outside, he might feel threaten or the need to mark up their territory. Actually, has it started since Nibbles visited?

Another reason is they could be protesting a habitat change. Like different litter material. Or a box was moved from where they like it. Some buns can be very pedantic. Lol!

I am thinking it might be baby. it is only in his cage he is doing this, and baby has been digging rediculously in their litter box. and he has gotton frusterated with her a few times that I have seen with her trying to mount him.

Ah. Bring on the 3rd then! Hopefully this will only be a temporary thing then.
It's good they aren't really fighting though. Small blessing.

In the meantime you could trial a cover (like a grid) that sits over the litter, and give Baby a diggy box to mess with. Cardboard and paper.

hmm good Idea