Next time just tell her that all your husbands were antifreeze intolerant.
Quote from a Henny Youngman skit:
I met a friend the other day, hadn't seen him in 20 years. I asked him how he was doing. He said terrible, been married three times, every time the wife died.
Well how did your first wife die?
She died from eating poisoned mushrooms.
How did the second wife die?
She died from eating poisoned mushrooms too.
Well how did the third wife die?
Fractured skull.
How did she get a fractured skull?
She wouldn't eat the poisoned mushrooms...