I'm not telling my roommate I saw his dick

I've been so conflicted about this for the last couple days. "Quick" story, I live with this guy, I'm a girl, and I think that could be kind of uncomfortable on paper but this man is the sweetest. Like, terrified of making me feel unsafe because of him being a guy. Not in a way that he's always walking on eggshells around me, just that he's very dedicated to making me feel safe. Imagine the kinda guy that gets very stressed about walking behind women at night and ends up crossing to the other side of the street to avoid scaring them. It's pretty cute. So okay, I saw his dick. Kind of a lame story, I just woke up very early, passed by his room and his door was just open enough that I accidentally sneaked a peek. Summer's been rough, he's been leaving his door cracked open for months and we never had a problem, but I think his cat pushed it open and I just happened to wake up before him (rare). Bad set of circumstances. I just closed the door a little and went back to my room. I figured it'd be nice to give him the privacy, but also I realized that if he found out he'd flashed me in his sleep it'd probably fuck him up. Like, for the usual reasons you don't want people seeing you naked, but also because he'd spiral over making me uncomfortable. I had to insist to this same man that he could be shirtless around me, so imagine hanging dong. But then I've also been feeling a little shitty for \*not\* telling him. Isn't that the kind of thing you should let people know? I feel burdened with knowledge. But then he'd feel awful and be convinced he made me uncomfortable. Truth be told, this is anonymous, I liked what I saw, big whoop. But obviously I'm not telling him \*that\*. So I've settled on keeping the secret and waiting for winter to arrive so I don't have to face that moral dilemma again.