Me and my boyfriend were both 18 at the time but still were relatively inexperienced as we were each others firsts. He was super vanilla and honestly really innocent in bed, so he would always rely on me to take the lead. We were sitting together on the couch on day after classes and I saw him scrolling through his phone. One picture of his friend popped up, and she was wearing a skimpy bikini as she had just been on a trip to Hawaii. I saw him like the photo, then he paused, looked at me for my reaction, and he had a kind of nervous face as if he made a mistake. Honestly I’ve never been too protective of my boyfriend as I know he’s too introverted/pure to actually cheat on me so I kinda just laughed it off and told him that I seriously didn’t mind. He told me okay, and that was the end of the conversation.