Friendly fire needs to be an option for supports only.

ADC: "BARD WTF, THERE WAS NO REASON TO ULT THERE, YOU FUCKING KILLED ME."
Bard: sounds of uncaring and no regret
I will totally not Lich Bane my ADC for being the idiot they are constantly
"Accidentally"[slayer-jinx-wink]
As a Sona main I live for teamfights.
Teamfight? Oh, you mean that thing when we slaughter the other team.
BARD WTF WHERE ARE YOU!?
happy chiming as he roams river collecting chimes
mid is asking for assistance
god-like stun
Double Kill!
Shitty support never botlane goes in 1v2 and dies
Malevolent chiming
Even when your support is 7 levels behind your mid and top laner, they are still more useful than Sakura.
There are moments where this comes to my mind
Tfw your teamfight and the support is farming top lane. Happens to me more often then you'd think :/