This is so sweet. I feel like his bf is jealous ofc cuz misuzu has known sanada longer than him n it's fine to be jealous. But misuzu is just really happy his friend is having a good time with him finally. Although I feel like sanada has feelings or misuzu, if not, then his bff is being kinda mean to sanada. Like imagine ur trying ur best to patch up ur friendship despite all the difficulties before, but ur bf's bf is too jealous to let u enjoy the friendship 😭