It turns me on that they search for my wife

I'm going to tell them what's been happening, my wife and I are both 32 years old, we have two kids and we've been together for over 15 years... she's a brunette, 1.60 meters tall, with normal breasts but has an amazing ass. It turns out she's in college and well, they start doing those study group things, there's this guy in her study group who's 19 years old and keeps sending her messages supposedly all related to studying and it's hard for her to read them, but the other night while reviewing his phone I saw a message from him that said now I'm going to sleep thinking of you... what I couldn't do was open the message because she would find out. What I did see in her photo gallery on a blocked folder were photos she never sent me or I had seen before. The truth is, I started getting annoyed at first but after just thinking that my wife is getting it on with this guy, I started to get hard and feel bad. While looking at her asleep completely naked, I imagined how this dude would screw her, the things she'd teach him, they'd both enjoy them and so would I because the idea got me hot. My head's a bit perverse but well, over time I'll realize more things. What did strike me is that I wouldn't mind if someone else screwed my wife and especially if I could watch... These are the photos I found