Tim wasn't quite sure what to make of the mischievous look in Harry's eyes, but when the light touches quickly became a well coordinated tickling attack, he couldn't stop the laughter. "Sto-Har-Please." Words were fragmented as he squirmed and giggled, not quite fighting too hard to escape his grasp.
After a few minutes, he became painfully aware of just how aroused he was getting from the tickle attack. Tim suddenly got kind of nervous and shied away from Harry and his tickling hands. He tried to stuff some of the comforter between them to hide the evidence.