Uh, oh, well O not being neutered could cause a riff. Even if he doesn't directly fight, his strong "unneutered" scent can signal territorial dominance issues that challenge Aftias, which inturn will create dominance displays via their poop!.
So, you really have a challenge in bonding these two. Two male is difficult enough, but having one of them not neutered yet can add to problems. (I know your vet there won't do it until he's six months old) I know here they usually only wait to do females until six months.
Aftias seems like he would deal with a dominant bunny up to a point. He is showing enough annoyance and dominance to tell Odisseas when enough is enough, but the fact that Odisseas hormones are driving him to be territorial, he may push it until a fight breaks out.
I also am figuring you will have poopwars for as long as the can smell each other and until they work things out.
So here's what I suggest:
1. Don't try to bond until Odisseas is neutered and his hormones have died down. I know this is three months unless you find another rabbit savvy vet that is willing to do neuter Odisseas now. Otherwise, you will have poop all over the house.
2. You may even need to completely separate them in other rooms and not allow them to see each other to help stop the poop issues. They may only then poop near the room where the other is staying - like by the closed door.
3. You can try and get them used to each other by using a stunt double - check out my bonding section regarding that. http://www.binkybunny.com/BUNNYINFO...aspx
(you'll need to scroll down) Note: if you bunny ends up digesting the fur of the toy bunny, you'll need to take it away.)
4. When you do bond, do what started to do - go slow in the bathroom. Mounting is fine as long as there is not fighting back. You can help by petting the one that is being mounted. Keep things short, and do several sessions a day IF possible, and slowly increase time.
5. If they begin to show true aggression, then you may need to do the stessor methods prior to having them meet in the bathroom - like a car ride.