The translators notes "GG" 😂😂😂😂😂

What does 'GG' mean?

Good Game

Is it an inside joke or something? Because I still don't understand why it's funny...

._.

it's normaly used in game-chats after the end of a match to let everyone know it was a good game or to say well done, but you can also use it in a sarcastic way wich is the way it's used here http://www.mangago.zone/read-manga/take_care_of_my_housekeeper/uu/take_care_of_my_housekeeper-chapter-8/33/
in this scene it's more used as "well done you fucking idiot" (because it really wasn't "well played")

I dunno how else to explain it but when a friend does something stupid I sometimes say
gg wich you can basically take as "well done you fucking idiot"
anyway I tried ε=ε=(ノ≧∇≦)ノ

Oh, I get it now. Thank you for patiently explaining it to me. :)

Is something the matter? O.o

Its nothing

XD no problem^^