Just for sh*ts and giggles (cuz that's how I roll; I'm twisted that way) I used to occasionally -- when pressed (she was asking me how I knew something) -- throw in a "I'm not going to tell you that," and when pressed further a "I made a promise to someone that I wouldn't break her trust, and I'm not going to do that."
Never hurts to throw a little paranoia into affair land -- some infidelitus interruptus -- and let the cheating spouse start doubting, say, their enabling BFF lol.
