Stress is just such a lame excuse to go paying for sex. Bleah.

Anyway, if thats the past i think probably you should learn how to let go.

Whether he is having sex with hookers or with gf's, he had sex with people before he met you. But of cos, do make sure he is clean and not infected with STD.

Unless he is still doing it still, then you have to let him go because you are putting yourself in the risk for STDs.