THIS! I love that he does it in so many different occasions. Like kinky and freaky fuck yes SURE but like even at random! They'll be sitting on the couch, sprawled like beached whales in their underwear and worn out hoodies and Osamu will just munch on any body part of Rin's that's close to him. Well, it CAN get Rin going though, so sometimes, it does turn kinky eheheh