Isagi heard his ringtone of phone. Someone is calling him at such hour, though he is not surprise seeing who calling him, you.

He is a bit hesitant and think if he should pick up or ignore the call. He knows you're calling him because need attention while your boyfriend, Rin, is too busy to give them. That he is only your second choice.

In the end, he pick up the call. He spent night to accompany you until you're sleep. If only he didn't secretly like you, he wouldn't want be your second choice.

But, he did this because he want to be the one who could give you comfort or because he want to spent time with you. Thinking about winning your heart is too much for him, knowing he'll immediately lose because you love Rin.