lichess.org/dpduBxtX/blackYou didn't see that coming:) #quicksilver
From white's perspective.
White already had a substantial advantage. 3...b6 and 4...c5 was loss of time. Either 3...c5 or 3...b6 and 4...Nf6 make more sense.
I did see it coming, but I'm impressed that you saw it coming at your rating. Good job.