Just found this quote from one of Sandi's old posts that is helpful:

"The H needs to make her WORK to get him back, and one night of sex isn't work for her. Work for her is getting her heart right, ending her wayward ways, start showing respect and devotion to her H & family, behaving like a decent woman, and apologize with a broken heart for everything she has done to her H and the destruction she's caused. That's the real work. And trust me, it is not sudden. It is not going to be one of these overnight things. Coming out of waywardness is not a quickie for most women. It is painful, and part of her pain should be remorse she feels, not some self-centered pity party she's having."

So it seems like agreeing to attend a dinner party and acting as if everything is fine in our MR is allowing my W to eat cake: she's disrespectful and cruel when drunk but gets the upside of a husband when it comes time to socialize. Looks like I'm telling her no dice on the dinner.