I'm assuming HK means Hong Kong? either way, I'm sure there is some place you could find affordable stacking cages for two animals. royals definitely don't require as much vertical space as you've given them in your setup, especially without anything to climb and utilize the space. your head is in the right place, but it's really in the best interest of you and the snakes to separate them if at all possible. otherwise, I would just dispose of any eggs that might result and keep doing what you're doing. can't argue with the fact that this is your first 'incident' in twelve years, no matter the circumstances.
for what it's worth, from that picture, it looks like you might be dealing with two males and an aggression issue. I've never seen it because I haven't ever kept two males together, but that doesn't look like a typical lock. it looks like only one hemipene is jammed into the other snake's cloaca, without the usual place for it to be received. take that with a grain of salt, but I'd keep this thread updated if you want to solicit further information from people with more experience. have they separated yet? does one seem to be hogging the warm spots? anything else unusual besides both going off feed?