It's OK to celebrate your success, but try not to be too 'smug' about it.
You can wipe that 'smug' look off your face.
a 'smug' smile/expression
(..) You and your son can go now, Mrs. Parr. I'm sorry for the trouble. You're letting him go again? He's guilty! You can see it on his smug little face. Guilty, I say, guilty! Dash, this is the third time this year you've been sent to the office. We need to find a better outlet. (..)2004 The Incredibles