Honestly, Beast, we can't all be perfect little angels to each other all the time, and as long as that isn't a regular occurrence I wouldn't worry about it. He engaged it, he should have been prepared for a bite. I wouldn't dwell on this like it's a huge deal. He probably wasn't meaning to mortally offend you, so try to look at it from his perspective. He could have had an abusive partner back home that would play sadistic games with him like making him call people that, but really inside he's benevolent. He could have… whatever, all of my random stupid shit aside, I doubt he's giving it much thought, and I don't think you should either. Whether you're in a perfect state of mind ("I was having a perfect day, and this guy ruined it!") or in a turbulent state of mind ("After a long day of acquiring bread and placing it on a table, this is what I have to deal with!?"), people will eventually get upset at things and that leads to unfortunate occurances.
If you were particularly snarky with him, you may have jump-started his life again and led him into deep introspection. Why was he calling you that? Is he so secure about his sexuality, himself? He may come back to you a very different man. Maybe he'll dust off that old motorcycle he had decades ago and ride off into the sunset, off on a journey to find these answers about himself.
But seriously life shouldn't be a constant stream of uber-polite distanced peace, I wouldn't worry about it.