Khloé Kardashian and Tristan Thompson have "been seeing each other for a little bit".

Khloe Kardashian

Khloe Kardashian

The 32-year-old reality TV star spent the weekend in Cabo San Lucas, Mexico with the 25-year-old Cleveland Cavaliers player and sources close to Khloé have revealed that they have been dating for a while.

A source told PEOPLE: "Khloé and Tristan have been seeing each other for a little bit. He's a really nice, good guy and she seems very happy with him.

"It's unclear for now if it's going to turn [into] anything super serious, but for now they're having a good time together."

Khloé and Tristan spent the day at a Beverly Hills mansion last week, while they also recently partied together at Bootsy Bellows nightclub in West Hollywood.

Meanwhile, Khloé recently revealed she is worried about her estranged husband Lamar Odom after hearing he is "hanging out with bad guys again" and is worried he will slip back into his old ways.

She said: "I've been so worried about Lamar. I just want to keep him around positive people ... I am so conflicted. I want the best for Lamar, but with everything going on lately there's not a lot of trust there.

"Everyone wants to see Lamar do well and succeed at life. Everyone was routing for Lamar, except him ... Nothing is going to wake him up, that's just the way it is. This is Lamar."

Khloe has been particularly worried about Lamar slipping back into bad habits ever since he was found unconscious after a drink and drug binge at a Nevada brothel in October 2015.