You don't compete...
You say they are ratchets, which I'm not sure what that means, but I'm assuming it's the same as a uk version of a skanky chav ...
If that's the case why the hell would you want to even try to compete, don't lower yourself to that level ...
Men are weird, ( no offence guys ) we will never understand them, loads of guys have wife's with big boobs but actually prefer small boobs, but they fell in love with that woman for who she is not boob size...but it doesn't mean they are going to stop liking small boobs they will still enjoy looking, but that's as far as it will go...if you weren't enough for him, he wouldn't just be looking, he would doing with these girls...don't you think big girls feel the same when there husband are constantly watching slim girls....men don't understand how women are body conscious...
Is it such a big deal that you caught him jerking off, i mean be honest don't you masturbate, it's not something women are as open about like men, but we all do it...possibly more than guys do lol....
He is not going to change so maybe its worth finding someone who worships you..I would of left his *** the minute I found the sex tape with his ex, not an image you want burnt into your head, a man who respected you would not want you to find that, why would he want the memory when he's started a new life with you