In general, she is a sweet, feminine woman and I am her man. But I've noticed a pattern where she becomes unpleasant for me to be around, whether that be snarky answers to questions, put downs, or just general bitchiness.

Ex. Last night we were out with another couple. The guy is a great friend and one of the most RP guys I know, always a good time. His wife is fun too. After a handful of just general snarky comments (imterspersed with normal ones), my buddy and his woman raise there glasses to a recent accomplishment of mine( after frequently mentioning it through out the evening), and my girl chimes in with "oh, yeah, cheers to whatever it is we're celebrating" ...and I can't help but burst out laughing at her. Like, da fuck? So I laugh at her, thank my friends for the congrats, and move on with my night.

She does this in front of her friends (she suddenly thinks she's king shit or something) and in front of my family sometimes.

How do you deal with this behaviour? On the one hand I would think a RP man wouldn't even notice; water off my back. My problem is that it happens in front of other people, and I've seen it mentioned to "shut that down right away". How do you do that without appearing butt hurt? I imagine my laughing at her was a good start, but in general this behaviour of hers is too rude for me to let slide.