^^^ What ovrrnbw said.

Here is what I see from an outsiders perspective from this convo.

Later went to pick up my S from the preschool my W works at. Talked to her briefly:
W: So what’s for dinner? (Asking for S sake.)
Me: I’m going out tonight.
W: With who? (Asking for S sake, and testing/curious about social changes.)
Me: friends
W: what friends? (Asking for S sake and probing if OW exists.)
Me: you don’t know them.
W: who are they? (Now really testing your social proof, and being nosy.)
Me: Hockey people
W: where are you going? (Just being curious and furthering the convo, looking for clues.)
Me: Downtown (vague)
W (visibly upset): well I’ll be home later (This is telling me one of two things. She's visibily upset because you are being short, vague, difficult, and socially awkward TO HER PERCEPTION. For you rightfully so, because your time and plans are important. OR?.... She's saying "I will be home later" because she is having second thoughts about OM, or he is having second thoughts about her. She thinks she is the cat's meow, and is attempting to draw you back in as plan b on a string.)
Me: (gave her a thumbs up and walked away)