smirk 
(smûrk)
(smûrk)intr.v. smirked, smirk·ing, smirks
To smile in an annoying self-satisfied manner.
n.
An annoying self-satisfied smile.
[Middle English smirken, from Old English smercian, to smile; see smei- in the Appendix of Indo-European roots.]
smirker n.
smirking·ly, smirki·ly adv.
smirky adj.