Former professional cyclist Lance Armstrong is getting married to longtime girlfriend Anna Hansen.

Armstrong, 45, popped the question Tuesday evening at Lake Austin. In a photo posted to Armstrong's Instagram account, Hansen sits on his lap with a sparkling engagement ring on her finger while the sun sets in the background.

The photo was taken by Austin photojournalist Elizabeth Kruetz.

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"She said ….. YES!!!!" Armstrong posted on Instagram.

The couple met through charity work and started dating nine years ago. They have two children together – Max, 7, and Olivia, 6. Armstrong and Hansen spend summers in Aspen, Colorado, and the rest of the year in Austin, Texas, where their children attend school.

There is no word yet on when or where the wedding will take place.

Armstrong was previously married to Kristin Armstrong, with whom he had three children – Luke, 17, and twins Grace and Isabelle, 15. They divorced in 2003.