A: "You didn't open this letter addressed to me, did you?"
B: "No way! I'd never read look at else's mail!"
"There's plenty in the refrigerator if you want something to nosh on."
Not on your life!: Absolutely not! (a strong "no").
A: "Someone said you cheated on the test. Did you?"
B: "Not on your life!"
now and then: occasionally; from time to time.
A: "Do you see Jennifer often?"
B: "No, not really. I see her now and then, but not regularly."
nuke: heat in a microwave.
"If your coffee's cold, just nuke it for about a minute."
A: "Stuart says some really strange things sometimes."
B: "Sometimes? All the time! He's nuts!"