Whether it was in a separste volume or not, that last story's first page should have been a dead giveaway on what kind of story it is. Or perhaps a teenage boy stumbling upon a half naked man on top of anothernaked teenage boy and having a weird staring connection with the man when he looks over isn't a big "ding-ding-ding!!!!" for you. It sure was for me. And boy! Was it fun! :D
This one, you mean? http://www.mangago.me/read-manga/hand_which/mf/v01/c006/ Maybe they've changed the cover since, but that one is definitely NOT as clearly expressed as your description, or maybe I'm looking at the wrong thing, sorry if I am.
But you do have a point, I really don't pay too much attention to covers since in most cases they're really not a good reflection of what the story is (let alone being able to tell the age of young and not-so-young males, or young females and lolita-type not-so-young females).
It's not like I'm requesting the whole thing to be taken down or whatever... just a better, or more befitting description to each of the stories would have been enough for me. I enjoyed the other stories plenty, I'm just not a fan of paedophiles.
Give me a break, don't read anything that creeps u out, the rest of us are trying to enjoy these story's