OK, so if I were you: You didn't miss the play date, you decided to have fun with the kids yourself. All went according to plan and you really valued your time with them so you blew off your play date.
Old friends? No big deal-you got your reasons (though you {and I btw}) need to make new ones.
Telling your wife about the babysitter? I wouldn't. Wait til a kid mentions it. It's not like you're getting a play by play of what she's up to. Screw it. Then when she asks you say you went out. Tell her you went to a movie, it don't matter.
