When I was little I was told that in the past it was a trend that gay men wore one earing and that depending on the ear they used it (on the left or right ear) it was supposed to represent if their preference was to be in bottom or top... However, I think that's kind of old, like half of my brother's classmates have one earing and most of them are hetero, or at least my brother is and he has one too. XD
You know male pop idols have made earings popular in men too
I read that right earring for uke and left for seme. XD
Oh god, I automatically thought of the "Right Earring Rule" where if a guy wears one earring only on his right ear, it means he's gay ლ(´ڡ`ლ)