1) The act of getting fucked in both ears at once, or
2) A person who is in the habit of being fucked in both ears at once, because his or her other orifices are already in use.
3) (Obscure) A very unfortunate accident with a donkey.
Originating in a town in the North West of England known for its 'welcoming' young ladies. And its donkeys.
1)- Have you seen Stacy lately?
-Yes, Darren and I were over at her place yesterday, she was already pretty busy so we gave her a Blackpool Fingertrap and then got a kebab.
2) -Have you heard about Sharon?
-Yes, Wayne has gotten her knocked up.
-I'm not surprised, she's a complete Blackpool Fingertrap - it was only a matter of time
3) - Have you seen Jason about the town lately?
- Oh no mate, didn't you hear? Blackpool fingertrap. They had to call the coastguard.
- Oooh. Nasty