Scott Disick Celebrates 35th Birthday with Girlfriend Sofia Richie

Scott Disick has been tamed by a woman close to half his age.

Scott turned 35 Saturday and he spent it with 19-year-old gf Sofia Richie on St. Barts. For her part, Sofia is in hook, line and sinker, telling the world, "Happy Birthday babe! Thank you for being you. Love you."

The 2 have been together now for a year and word is they've gotten super serious.

It also looks like Scott and Kourtney Kardashian have made peace ... if only for the sake of their 3 kids.

Scott has a pilot in the works where he's flipping houses in the L.A. area with super realtor Tomer Fridman ... and guess who's behind the project? If you guessed Kris Jenner you would be correct!