I saw the description of a lolicon the other day but can't find it again. A girl is bored because her mom and dad are having spas and whatnot, and kids aren't allowed. So she gets ahold of this pass to a special massage, which turns out to be a sex thing.

Hope to find it~

Chimi Anal, I guess.
She gets a very "special massage" from a machine and is later gangraped, if y remember well.

Ahh, right, that's the one. Thanks!