Kyou mo Kitansu ka, Yoda-senpai. - Vol. 2 Ch. 24

[MangaDex]

 

[laeus]

I didn't know that kissing someone's hand could be so embarrassing. In some places, it's still a greeting.

 

[Monn12]

I didn't know that kissing someone's hand could be so embarrassing. In some places, it's still a greeting.

It's not, Japanese authors being weird and awkward once again.
Create an awkward guy who despite knowing fully well what porn is, get's embarrassed by small skin revelation from a girl. (Like people who live near the sea or have family family outings to any water source, can see a lot of women in their bikinis....So yeah, authors are just basement dwellers who don't have family and never visited schools)