If you want to try to work it out, I think you two have to figure out a few things and it may take professional help to do so.
One, what need, exactly is he filling with this activity? Is it as simple as enjoying the attention of women, or getting his rocks off, or is there something deeper? Is he somehow testing your feelings for him? Is they lying just adding to the thrill or does he actually think he did something wrong?
Two, do you want it to stop. And if you do, is he able and willing to stop.
Three, if you want it to stop, and he agrees to stop, what exactly will it take for you to trust him again?
One, what need, exactly is he filling with this activity? Is it as simple as enjoying the attention of women, or getting his rocks off, or is there something deeper? Is he somehow testing your feelings for him? Is they lying just adding to the thrill or does he actually think he did something wrong?
Two, do you want it to stop. And if you do, is he able and willing to stop.
Three, if you want it to stop, and he agrees to stop, what exactly will it take for you to trust him again?