Unsportsmanlike behavior
We all know what it's like. We lose lane and then our opposing laners get cocky and start BMing (Bad Mannering) us. Whether it be through repeated laugh animations or simply straight out rubbing it in through text. My question is: Why do you feel the need to do this?
We all know what it feels like. We've all lost at one point or another. So why then do some of us feel the need to make others feel worse about losing than they already do? Is it simply because people have inferiority/superiority complexes? Does it satisfy some primal urge for domination of one's competition?
I just played a game where I was Sona and my ADC was Graves. We went against a name and Vayne. We lost hard due to the opposing jungler's presence. We also lost the game. Both the Vayne and Nami (especially Nami) felt the need to rub it in despite the fact that no words had been exchanged at any point in the game. We did not BM them nor even say anything. I decided to report the nami. Sure she didn't say too much, but it should go without saying that I (nor anyone else) should have to deal with such behavior.
EDIT: I want to add since people are focusing hard about what happened in-game. Much of the BM occurred in post game screen while I was looking at the game stats.

), but I don't do this often, and when I do, it's usually something like "ha" or ":D" and never anything directly insulting. I would say I do this as an open expression of how I feel about a situation, and likewise, I sometimes type "D:" or "Aw" whenever I'm on the other end of the situation. I would also like to think anyone who finds small things like this annoying has all chat turned off.