Post your blunders

When have you lost the game in one move (excepting single-move piece hangs and back-rank mates)?
What are your "???" plays?

Here is one of mine from my most recent game, in which I show myself as a 1500 peasant:



In this position I had spent several minutes calculating the pawn race after 34...Bxe3, and so I played very quickly... up to 39...Kb4??? which instantly loses because White can now queen with check! Whereas if I sidestep instead to B5 or B6 then I have the time to queen my own pawn. The game would likely continue for a while due to the pawns on the kingside, but the tablebase states that Kb5 and Kb6 produce a draw.

Another example, from a miniature I lost a couple of days ago.
After 12...Qxe4+? I have the resource 13. Ne2 -- it's very important to see that my queen protects the g-pawn and thus the h-rook. After Ne2 Black doesn't have the time to achieve a mating attack with ...Bc4 since I have the accurate Nc3!
Or I can even castle, abandoning the knight, and Stockfish says my position is perfectly fine after 13. Ne2 Bc4 14. 0-0 Qxe2.

However, I played Kf2??? with the intent of defending the (already-protected g-pawn) and there is now a simple mate in three continuing 13...Bc4+ 14. Ne2 Qxe2+ 15. Kg1 Qe1#

If I posted all the blunders I made in a single session we'd probably up to page 3 already

In this recent example, I was White in a fairly equal endgame with just the passed c-pawn to worry about. I decided I would walk the king to be in front of my f-/g-pawns, and instead of going via H2 I mistakenly chose 31.Kf1? -- after the discovered c3+ I have to go humbly back to G1 and admit lost tempo.

But instead I continued into the jaws of death with Ke1??? after which 32...Ra1+ 33. Rc1 Rxc1# is obvious.

If I post my all blunders here then you will forget definition of blunder by watching those 😂😂😂😂

@FantasticTricks Once you realize that I played the worst move possible...:

When I gave up a piece at move 9 by capturing the pawn ...

@FantasticTricks lichess.org/k52HMLNk/black#44

I missed the obvious 22...hxg5

When I got crushed by a 1300 in 7 moves for Trying out a dubious opening..

This whole game by me is a blunder..

Now what do you say @SavageAntarctican?