Wife's Secret Office Obsession

So, my name is Alex and I'm married. My wife Sarah and I have a comfortable life, stable jobs, two kids in college, you know, the stereotypical suburban dream. But it’s week three of my company's mandatory WFH policy due to some health concerns we're trying not to broadcast widely, and let me tell ya, being stuck inside isn't as fun as those remote-working memes make it sound. This morning started like any other, I woke up, had a quick coffee, checked emails (which was already a little overwhelming after just the first day back), and then… boredom hit. It’s not that there wasn’t plenty to do, but when you’re dealing with corporate nonsense all day long, sometimes your mind wanders. As it did today, wandering over to my desk where I noticed something new: an unassuming USB stick labeled 'Office'. Now, this is the first time Sarah had ever put anything like that in here, and her usual habit is to leave notes or reminders for me about home things. Curiosity got the best of me, so I popped it into my computer. The file was a video link, click-baited titled 'Incredible Office Sex'. Skepticism and intrigue mixed together as I clicked. Sure enough, there it was: Sarah in what looks like our office room but decked out with toys and lingerie everywhere you look, undressing slowly while narrating fantasies about me. It turns out this wasn't a one-time thing either; the folder had several more videos and pictures of her engaging in various sexual activities alone or paired up with random male partners she’s been dating. She even mentioned our kids and that it was just for fun when I’m away, but also admitted she likes to explore these feelings. I couldn’t help but feel a mix of anger and arousal at the sight of it all. Anger for betraying trust we've built up over years (okay, decades), but damn if watching her so free wasn't turning me on in ways I haven't felt since early days. So here's my confession: Today while watching Sarah’s secret videos, I found myself masturbating to them, imagining the scenarios and being there for real, maybe even joining one of these dates or whatever fantasy scenario she's into. Am I the asshole? Should I tell her and confront this head-on, or keep it my little dirty secret?