he's the cheater then he doesn't let you to have a friend because he's afraid of you finding another guy???? what is with that?
sweet hear, stay strong and try to make a good decision....I'm thinking even probably it's better that he's not sleeping with you anymore....How can you trust him if he's clean without any STDs? now that you know he's sleeping around.....
If you are asking me, and if I were you, I would not let him to be close to me even for a moment.....I would never trust a cheater.....but this is all up to you to make a decision.....

take care of yourself and your son
you are in my thoughts
Marjan