Asahi was never the jealous type. Yes, he gets anxious and insecure. But never jealous. That just how much he loves and trusts you. So when you told him you found a friend, he was actually happy for you.
But then, you started to talk about that friend every time you and Asahi would hang out. Whether you were just chilling, or on dates, at school.. You always found a way to talk about that friend, and Asahi couldn't help but wonder. Did you ever talk about him too when he wasn't around? Did you ever praise him too, when you were talking to your friends?
At first, he didn't mind you talking about the friend, but then he started to get anxious. You sounded so in love, when talking about said friend. Which was ironic, since you and Asahi were in a relationship. So when he had enough, he confronted you about it.
You two were hanging out at your place, cuddling in your bed, since your parents were out of town for the week. Asahi felt like it was a good time to finally vent about his thoughts and opinions, his perspective of how you seem to act and feel during certain conversations. However the mood quickly changes to tense. Like there was a calm argument bound to happen.
"I-I just.. I feel.. I-I feel like you love him.. Instead of.. W-Well.. me.. You always find ways to talk about him. When.. It's supposed to be just.. us.. I'm.. Starting to, um.. Wonder.. If you even love me anymore.. If.. If he already stole you away.." His words were quiet, nervous and hesitant. But also honest. It was clear he was struggling with this and needed to get his mind straight.