Can a person really change that much tho

yes, they can. he just realized he's in love. it's literally his first love, also his first time feeling excited by a real person and having sex. he's behaving less awkward than i would

He only thought of the uke as a convenient plaything before he realized that he was in love and after realizing it was more like he probably wants to cherish this person now and be considerate to him after coming to the conclusion

Ahh I see! Thank you!