曾祖母のひ孫筆おろし ～ひぃばあちゃん、もっとしたいよ～

It's the end of the year. It's been two years since I last visited my great-grandmother.
Since it's been so long, I decided to take a bath with her, but...

(Here we go again...)

This is what's been bothering me.
Whenever I see a naked woman, or when a woman clings to me,
that embarrassing thing between my legs gets bigger.

"Kaoru, come in. I'll wash your back."

"Huh...? N-no, it's okay... I can do it by myself..."

That's the official reason. The real reason is my crotch. For some reason, I'm embarrassed about the growing thing between my legs. I feel like I shouldn't let great-grandmother see this. ...But I can't hide it, and she finds out.