Usually it's my opponent beating me once or twice (or even win the first game) and then teabag and fatality me. I mean what? Yeah I lost but usually I adapt and win later but I mean wtf?
Personally I'm only toxic to buttonmashers. If someone is spamming d1's, d3's and disrespecting frames and turns then after some wins I'll teabag a little bit, kill them and find another game lol. But other than that I see no point in being disrespectful.