According to sparkly shoppers in the Diamond District

“Say, ‘It’s not that I don’t want to marry you — it’s that I want to marry someone else.’ ” — Cecilia

“Slide the ring off her finger while she’s sleeping.” — Mike

“Tell them you’ve been engaged five times before, but seven’s your lucky number so you’ve got to keep looking.” — Ashley

“Say something like, ‘I kept imagining the rest of my life with you — and then I would get nauseous.’ ” — Tod

“Send a note to your family and friends canceling the wedding and copy him on the e-mail.” — Rachel