I don't have the Ocellaris clownfish, but I have a couple of maroons, which are generally considered more belligerent than the Ocellaris. The female maroon clown seems to be best buds with my regal tang. I frequently seem them swim up to each other and brush against each other, but not in any threatening way. I would say that they hang out together, except that the regal tang technically doesn't stay still long enough hang out.