Flying 1st class United from Washington Dulles to London Heathrow, and then a connecting flight on BMI to Dublin for some golf.
My question is can we deplane at Heathrow (with luggage), and skip my last flight segment without changing our tickets? I assume we will be going through customs in Heathrow with our luggage and could simply skip the last fight segment into Dublin?

Any help is welcome.
Thanks,
srmrktng