Earlier sempai got mad at him, in the previous chapter, he didnt want mori to feel like he was rejecting him or being mean to him like his family. Basically sempai didnt want him to take it the wrong way (while I think he was turned on by being so close to mori) he explained that his reason for getting mad was because he basically gets shocked by being touched (he has different space boundaries). Mori loves that sempai can now show worry better.
Senpai pushed Morinaga's hand away, and you can see Morinaga looked a little hurt. So Senpai spent the day thinking about how to let Morinaga know that he didn't push his hand away because he thinks Morinaga is disgusting, it was because Senpai isn't used to physical contact as well as Morinaga is. When Morinaga realizes that senpai was worried about not hurting his feelings, he felt touched and loved, so they had some cute yaoi sexy time :D
ok thank you guys i thought that "that "meant sex lol. I guess my mind is too perverted
I thought the same too...so I got confused
i'm not sure i understand this part well.