Nothing more annoying than this ->

#36 Lichess is better than chess.com.Here are many features to learn chess,lots of interesting variants,learn from your mistakes,opening book,titled arena tournaments in which competed world champion Magnus Carlsen.It is just your opinion that chess.com is better.Mine is opposite.

@AcademicNinja99 Just don't decline the draw by clicking. Either your opponent's time will run out or you can just move to decline the draw.

@AcademicNinja99 u can't cancel a draw offer, can u?

@chess-com-is-better

Oh, right, I didn't remember correctly, it wasn't a draw offer, it was a takeback!

#43 no under the rules on chess draw offer cannot be withdrawn

... thinking that you have just played a great game, only to find that computer analysis shows you made serious blunders or oversights...sigh..

@Davelz

Well, as long as you won the game, that's not so annoying XD

@MagicAce1988

Yep thats pretty bad.
Most annoying thing to me is when I have two games open; in two separate variants (Crazyhouse + Antichess)

And I have a super lead in both games.
Then I mix up the tabs and take a pawn with my queen in ZH...lol :l

Probably has happened to me 100x