Secret Recording, Secret Affair

I've been with my husband for almost 40 years. Married 31 years and 6 years before that. We are high school sweethearts. He's the only person I've ever been with. We have 3 kids all 18 or older. We also have a very healthy sex life. We don't have any hangups and let our inhibitions run wild to extent... Lol. We've never shared our bed with anyone else. We fantasize about another woman joining us. That's about it.

This weekend we had some drinks got a little drunk and we jumped into bed and did our thing. I ate his ass and sucked his cock, we 69ed and then he fucked me, pulled out and unloaded into my mouth. It was better than usual. Later on that night he got out of bed and went downstairs. He usually gets a snack or a drink and comes back to bed. Some time went by and he wasn't coming back. I went downstairs to check and there he is on the couch texting away on his phone. I asked him what he was doing. He was acting weird and wouldn't tell me what he was doing. I pressed him and he got a little agitated. I just said whatever and we went to bed. After he fell asleep a went to check out his phone. I looked in his email.... Nothing.... I then looked in his texts and saw a number I didn't know with a link sent to it. I clicked the link and it took me to a video of our sex we had earlier. I was shocked!...who is he sending this to? I called the number from my phone and an answering message began. It was some woman named Brandy! Who the fuck is Brandy and why is my husband sending an unauthorized sex video to her? I feel so betrayed! Is he fucking her? What should I do? Has he done this before? How should I approach this situation? Looking for some guidance...