happy face tell

Hello, I play in a pot-limit game with the same group of players I have a tell that is costing me money. Whenever I bluff/semi-bluff with a big bet I smile subtly. Everyone knows this and often a player will put me through the ringer and stare me down. After about 30 seconds of this I cannot control it and my grin slow turns into a big smile. I have tried many things such a telling myself a have the nuts, wearing sunglasses, or just straing at the pot, but yet I can't relax. Any suggestions?


Mark