Morse Code

Sherlock needs to get these dumb unrequited feelings out of his chest, so he begins tapping "I love you" in Morse Code every chance he gets whenever he's around that damned army man.

Based on the following tumblr post:
http://wearitcounts.tumblr.com/post/84265058802/wankerbatch-sherlock-tapping-i-love-you-in