How would you want your partner to react to finding out about this kink & your sends?

Just learned that my kids dad has been sending girls money for years, as recently as last week while we were having family Christmas. I’m completely in shock & heartbroken from the betrayal I’m feeling from all of the lies. At the end of the day, I’m not kink shaming, I’m not shocked by his sex addiction, I’m just mad about the hiding the $ part. He’s made me feel guilty for how I spend then I find out what hes actually doing. I saw transactions from at least 2yrs back. Seemed a little inevitable that he’d eventually slip up despite trying so hard to hide it, so my question is, from those in his same kinky boat, if you got “caught” by a partner, how could they best handle the shock? Bc honestly I would have been his dom very very painfully well if I knew that’s what he wanted but I’m guessing he doesn’t see me that way as the mother of his kids. We’ve been rocky in this stage lately but I still love him, but I truly don’t feel that him being in a relationship is what he needs right now. So how do I move forward?