Hi and welcome.....
Frankly, and no offense, your father's "advice" sucks....He's only excusing his own behavior by aligning it with your husbands. "Boys will be boys..." Oh honestly...

Don't buy into it. It's wrong and you deserve to have a faithful and loving marriage.

That said, if he doesn't want to change, then he doesn't want to change....

My sister in law was in a similar situation....he refused to seek therapy. She went alone for a while to help sort out her feelings and what was important to her.

I hope I didn't offend too badly. I tend to tell it like it is. And sometimes we're so deep into our own **** that we can't see clearly.

The most important thing is to treat yourself well, in whatever manner you are able.