Just showing up as Wendy! That's called an ambush, and that could go from fantasy to nightmare real quick. And I have to agree, as these are mutual friends of yours and your wife's I would not even think about ti with out talking it over with her. You might not care about lossing this other couples as friends, but your wife might, and there is no way they would not tell there husbands, why whould they keep quite about it, I am sure it is not their fantasy!