Sofia Richie and Scott Disick have reportedly called it quits.

The 19-year-old daughter of music legend Lionel Richie is believed to have called time on her romance with the 'Keeping Up with the Kardashians' star - who has Mason, eight, Penelope, five, and Reign, three, with former partner Kourtney Kardashian - nearly a year after they were first spotted getting close.

A source said: ''Sofia broke it off.''

The break-up is believed to have occurred after Scott was spotted cuddling up to a mystery woman earlier this week in Jackson Hole, Wyoming, just days after the couple returned home from a romantic vacation to celebrate Scott's 35th birthday.

Sofia's family is believed to have played a role in her decision to leave the notorious partier, as they insisted she ''deserves better''.

The insider added to E! News: ''Her dad got to her and was a major influence. He told her enough is enough and she deserves better than this. He told her to come home and she did.

''She is upset and sad but feels like she had no choice and she couldn't stand for being cheated on and being in such a toxic relationship.

''She is relying on her family for support and they are trying to keep her busy. She is spending her time with them and with her close friends.''

The split comes just days after it was reported that Scott's former girlfriend Kourtney, 38, now ''trusts'' Sofia with her brood.

A source said at the time: ''It helps that Kourtney now trusts Sofia. The kids are allowed to spend time with her. Sofia likes having them and helps Scott. So far, the kids are giving Kourtney good reports about Sofia.

''Sofia has shown over and over again that she is willing to stay with Scott even when things are not great - but Scott is doing well lately. [He] isn't really partying and spends a lot of time with his kids.''