Katsuki was having a shower in his dorm room bathroom. You had gotten a bucket of cold water and a stool into the bathroom without him noticing. You got onto the stool and poured the water onto him, making him shout, "AHH AHH HA HA" he laughed and opened the curtains, wrapping his arms around you, making you scream and then lose balance and fall back onto him. You were both laughing while sitting in the tub. Yes the shower was still on