Woman with motor neuron disease touched by boyfriend's surprise proposal

Scotland (WPVI) -- Lucy Lintott thought she was posing for a picture with her boyfriend, Tommy Smith, at a charity event in Sterling, Scotland.

To Lintott's surprise, Smith got down on one knee and asked her to marry him.

Lintott, 24, was diagnosed with motor neuron disease (MND) in 2013, and has been dedicated to fundraising and campaigning to find a cure for the illness, according to Storyful.

Lintott said she's known Smith since school, but they started dating six months ago after reuniting at a charity event for MND Scotland.

Lintott's friend Lucy Cortis captured the video of the touching moment when Smith proposed.

On Twitter, Lintott shared the video and wrote, "When you know, you know!"

Congratulations to the newly engaged couple!