It wasn't my fault. The conversation went like this.
I was playing Nexus Siege as Azir, I was laning against Teemo and beating him up.
Kat comes in to gank me, but I see her coming and take the fight to her. She kills me, but my turret kills her.
Me: yeah no. (Referring to her attempt to gank and escape unscathed)
Kat: Still got you bby. ;)
Me: Well I got you too bby. ;)
(I'm unfortunately not very knowledgeable about internet abbreviations, so when I saw bby, I thought it was some kind of friendly name like bro or dude, so I responded in kind.
Teemo: **** off Azir, she's mine!
I then realized what I did and quickly typed as I respawned.
Me: I didn't know, she talked to me first!
Kat: I'm a public commodity.
After that point I ignored them and went ahead to win the game.
A quick Google search afterward gave me insight.