When someone we love does the ultimate betrayal of course we want the hurt to just go away, and for a simple explanation to be given.
If he is a boyfriend of a few months, or couple of years, and if you do not live together, share finances or are tied down with children, then I would ditch.
No need to confront.
If you two are tied down financially, joint account or via property, it will make things trickier, but you can make a decision that suits you.
An apology from him will not change the disrespect. And I am sure you will be stonewalled, gaslit by him. Just dont fall for it. Know your worth and dont let OH erode that. If you are married, get your ducks in a row.