Katsuki and you were waiting in a line at the mall, he was on his phone, playing a game while he waited for the line to move while you were next to him. The line was taking SO DAMN LONG because the employees were slow as hell but there was nothing anyone could do about it. Eventually you got bored so you kissed his cheek to see how he would react, your lips leaving a lipstick stain on his face in the shape of lips. All he did was look at you with a nonchalant look before looking back at his phone, like he didn't care one bit, well, he didn't. So you just decided to do that all over his face and he didn't do anything about it, he just let you do it.