Some People, Man
I was just in a game, just some normals, playing Trundle top lane. I'm a Twitch ADC main, and he's been easily my favorite champion in the game for 2 years now, but this game I felt like playing one of my least played champions.
The subject at hand, though, is our Twitch. He did pretty poorly, like 3/12 I think was his final score, and did basically nothing but feed their Draven for the whole game. I got enough team gold in turrets by ramming my club up their Riven's asshole so far she the tip came out of her mouth to make sure that the team wasn't behind, and despite everyone on the team ending with negative KDAs, we actually won.
I tried giving the Twitch some tips, particularly relating to teamfighting and builds. Twitch naturally loses some matchups, and Twitch vs Draven is one of them. He rushed BoRK, something you should only ever do on Twitch if you want to crush lane hard and snowball. How Twitch beats Draven is by surviving, farming, and not feeding him. Despite the Draven having 15+ kills, he had less farm than Twitch for the whole game, so at least he got the outfarming part right. Well, 30 minutes into a 40 minute game and he still doesn't have any AD beyond the like 30 that BoRK gives.
I simply told him that he shouldn't rush BoRK into losing lanes, noting that I'm a Twitch main, and he responded with a prompt "fuck you I do damage."
He didn't do any damage, he was dead too often and never used his stealth to flank and blow the enemy team's backline up when they're too distracted by me, Jarvan, Galio, and Thresh diving on their asses and CCing them into oblivion to fight back.
After he finished his IE, though, the last 2 teamfights were easy to win, rather than just barely winning or even losing most of them, and we got a win just by the scaling of our team.
I offered to friend the guy and help him learn Twitch so he didn't have to the hard way, and even sent him the friend request at the end of the game, but I don't think he's accepted it.
TL;DR: Know the difference between when someone is trying to help you learn and just being a dick, and respond accordingly. Don't be like this guy.