Snake yawns frequently, is it bad?

[Bogertophis]

That's something I haven't heard yet. He ate Thursday. But he's been doing this since I have him, three weeks. And he's had three meals with me so far and it didn't seem to affect the yawning when his meal was.
I suspect he is going too shed sometime soon since his color became dull, he has little flakes on his skin and his belly is pink. He hasn't shed since I've had him but I don't know if this could have something to do with it.

Okay, so if he was doing this from the start & he's eaten several times with you, that's probably not it.

Shedding IS another time they may yawn- that's to loosen the old skin around their mouth so it comes off with the rest of the shed. But that's normally only right before they actually shed. I have no idea why he'd be yawning for this long a time.