John walked through the sitting room door, dropped the soggy carrier bags on the floor, and sighed.
"Milk. Forgot the milk. Ow, hey!"
"Oh, John," Sherlock looked up from his book, startled. "Why are you all wet?"
Before John could remove his jacket, something blue and sticky just below his lip caught the detective's eye. He leaned down for closer examination. Unlikely to be harmful, but still… Just as he rubbed his thumb over John's chin to remove the substance, the shorter man jerked his head upward, closing the distance between their lips. Sherlock pulled away in shock.
"J-Jawn?"
After a moment of confusion, John noticed the thumb now covered in blue goo, and dashed down the stairs into the icy curtain of rain.