mc could have fucked every single girl on page 1 if he wasn't such a pathetic low test beta cuck
Leave him be, his bro love for his gay friendo Takt is to strong. He wants to stay pure, for his bro, when he finally gets balls and comes out of closet that he is gay and wants what MC has in his pants for himself.
Or at leasts thats the explanation I tell myself given the evidence in the manga to explain MCs behaviour.
EDIT after reading the chapter
: Yako once again shown to be the best girl (at least in my eyes) with her modestest breast size.