Buying dick growth drugs that force the user to have sex to get rid of it, is a quick way to end up getting dicked down by the recipient, but I guess Imouto didn't factor in that step when she bought them for her sister.
little sister: gives big sister dick growing drug to get her to go outside little sister: gets raped by big sister little sister: surprise Pikachu face
Base +7, 44inf +6, Azura Meta +6, ghoulishtie +7, TUSF +6, as102 +13