KAGEKI
It stinks.
Either they have never seen porn before or they just don't have a boner at all.
You know, that's probably the most logical reason for someone not to have sex.
Hmm...
Well, another reason this is happening is because men are being raised to be afraid of women, sadly. They are raised in a culture where women can string a man along with the promise of sex, so I guess it makes since if they aren't seeking sex because they don't want to get used.
I don't know how it is in Japan, but where I live, women can manipulate men so easily, it's not even funny. It's why I don't go out seeking sex, because a woman will have some strings attached like: "Buy me this, take me there, blah blah."
If I was dating and going steady with a woman, sure why not, but if it's just meaningless sex no thanks. I'm there for me and me only, I'm not your personal bank nor am I your toy.
You know, that's probably the most logical reason for someone not to have sex.