Well, it's highly unprofessional to entertain sexual relationships with one's own students, even if it was legal.
BTW, which younger Chinese students wants to "copulate" with fat, old and ugly-looking laowais?
Why art thou Romeo?
Is it because you copulated with your own students while teaching them, as at least two so-called teachers there

Some seem to bizarrely find a slight belly cute, and some girls just find Chinese boys to be too weak and skinny actually.

Still, it takes two to tango and those teachers are perfectly capable of saying no. I seem to have a little fan-club of teenage ex-students myself (well some are no longer teenagers, but...), but I am sure that there are lots of perfectly capable boys of a more suitable age for them out there. I personally believe in the 'what if she was your own daughter' approach, I ask myself the question: Would your slightly older self banging a pretty yet rather naive 18 year old student, really be that appropriate?