I know I keep asking but I’m so confused. I’ve never cheated on my ex

And I feel like he cheated on my because I don’t know why we both have a std and neither one of us cheated. I know he cheated on me and he keeps lying about it. I broke up with him because he’s lying he keep trying to say he got it from improper hygiene Leno way you can get 2 diseases in one and your not cheating. He brought that shit into our home. I got a feeling he has been cheating on me. And he’ll never tell the truth becaus he lies about small shit such as drinking. I need closure and I see he’s not real enough to give it to me