Sam and Doug met at Lockheed Martin's new hire orientation where Sam was oblivious to Doug's existence. Eventually, through their dogs and friends, the two became more acquainted and slowly grew closer over the years while working on fighter jets. They both ended up in Colorado where they got engaged on the top of an outdoor mountain chapel in the Grandby Valley.

(Thank you Hobo Steve)

TLDR: Boy meets girl, girl ignores boy eventually girl acknowledges boy and his dog and they get engaged.