Ahegao? (Not a lot, but there are a few panels of it.)
Also, a suggestion, new tag: unusual pupils (for the heart eyes [Fakku seems to have enough to warrant this, no?] or any other types that any artist might come up with.)
Find yourself a cute yandere girlfriend who is addicted to your smell and she'll love you for all eternity and never leave you (or let you leave her)...
(By the way: there was a similar story about a female teacher who fell in love with her student because of his smell, can somebody remember the name?)
Well, I guess in Hentai, the smell of a Hentai Protagonist's dick to a girl is probably like silver vine to a cat.
And also, the way that other guy so naturally just locked them inside makes me wonder if he knew and did it on purpose...
Something about seeing heart shapes in the girl's eyes are just really nice, I quite like it.