Khloe Kardashian is "done with Tristan Thompson for good"

A source said: "Khloé has moved on and is happy in her new relationship, which is still in its early stages. Tristan would want nothing more than to be back with Khloé, so of course, there's jealousy there."

The insider went on to add that Tristan- who has three-year-old daughter True with Khloe - has tried "countless times" to reclaim the affections of 'The Kardashians' star but to no avail, as she is confident the relationship is over and that they are "strictly" co-parenting at this stage.

The source told E! News: "Tristan has tried several times to win Kourtney back but she's done with him for good romantically. They are strictly co-parenting. They are amicable and spend time together when it comes to True. Tristan is single and doing his thing, but is not dating anyone special. He just likes to party and flirty with girls, which is nothing new."

While it has not been confirmed who the Good American founder is dating, Khloe - who was also married to Lamar Odom from 2009 until 2013 - was said to now be seeing a private equity investor introduced to her by her older sister and 'Kardashians' co-star Kim, 41, and reportedly went on a date with him towards the end of June.

A source said: "Khloe is feeling really good with her new mystery man!"