For the past week or two we've not attempted to get the bunnies together, relying on less direct contact between the two of them. Their cages are only about a foot apart, so they have plenty of opportunity to see and smell the other rabbit, and they both use the same room as a play area, so the territoriality was limited pretty severely. At first the two of them would leave each other little "this is mine" poops around the living room (keep in mind that rabbit feces are small dry pellets, and that becomes a much less disgusting image), but in the past week that's largely stopped. We got into a routine where we would alternate who came out to play first, and after half of the allotted play time had passed, we would surround the first bunny in the pen, and let the second bunny out to romp. They could get close enough to sniff noses, but we supervised to make sure that this never ended in nose biting, which was a danger at first. We even encouraged them to spend time near the other rabbit by placing tasty treats on both sides of the pen, as you see above. Bunny bribery is quite effective.
We, and they, had become so comfortable with this routine that when Jupiter hopped up on top of Juno's house it didn't surprise or worry anyone, Juno included. While Juno was out last night she was as relaxed as we've ever seen her, sprawled out on the floor next to Dave's home base on the couch. I've been reluctant to get the two of them together because everything had been going so smoothly, but we decided that as long as she was so chill, perhaps it would be a good time to try it out. They largely ignored one another at first, with the exception of one three foot chase scene where Jupiter was startled and ran after Juno very briefly before growing disinterested. We were entirely pleased by that reaction, since ignoring each other is a very peaceful reaction from critters that are very territorial by nature. We fed them each a carrot while sitting right near the other, and thought it was a pretty good evening. We were still sitting on the ground with them, petting and talking soothingly, when Juno slipped over to Jupiter and started trying to groom his hind legs for him. (He needs some help in that area, I must admit.) The first time she tried it, he immediately hopped up and moved a few feet away, but Juno has definitely decided that Jupiter should be her bunny, and determinedly tried again. The next time, Jupiter put up with her attentions for a while, only moving when she moved up his back with her licks. We were delighted.
We figured that the night was over when Juno headed back to her house, but before we could grab him, Jupiter had hopped right up in there with her. We were all set to grab him and pull him out, as we had no intentions of stretching their tolerance that far, but Juno was completely unaffected. We cautiously let things continue, and Jupiter hopped up on Juno's ledge with her. She still didn't care. She already seems quite fond of him!
Things backtracked slightly this morning while I was making breakfast. Dave let both of them out, and they were fine together, but Juno decided to go visit Jupiter in his house, which he did not especially appreciate it. Dave hustled her out of the cage (Jupiter was right behind Dave with his own ejection plan) and we shut his front door but left his top open. Jupiter is a much springier rabbit than Juno, and has no problem exiting via the roof, but Juno can't get up there to get in. At the moment they are both sleeping in their own houses, but the doors are both open so that they can go visiting if they like. Eventually I would like them to both live in Juno's expandable house, so it's very encouraging that she has so little objection to his presence.