I think only after you tell us more can we help you to decide what to do.
For example, why did you have sex with him? Because he is handsome?
Because of money? Because you wanted to get promoted?
Because you wanna him to get better job?
Because you wanna him to free you from getting outside China?
Or only when you were lonely and he seduced you?
Or he threated you, so you yielded?
THis helps us to tell if you should revenge him or if you can let him pay.