Khloe Kardashian and Tristan Thompson are ''half serious and half joking'' about having another child together.

The 'Keeping Up With the Kardashians' star split from the basketball player over a year ago but he thinks their two-year-old daughter True ''needs a sibling'' and she recently insisted the only way they will have a second baby together would be through artificial insemination.

A friend told PEOPLE: ''Khloé wanted to become a mom for years before she got pregnant with True. Being a mom is even more precious than she could have ever imagined. She just loves it all. She absolutely wants a sibling for True. Tristan seems to be on the same page and would like a sibling for True as well.

''Although being co-parents instead of being together is not the ultimate situation in Khloé's mind, she is very happy about how she and Tristan are raising True. And now with the lockdown, Tristan has been in L.A. for weeks. He and True are spending more time than ever together. Khloé is very happy about it.''

In scenes aired on a recent episode of 'Keeping Up With the Kardashians', the couple discussed having another child together after Tristan advised his former girlfriend not to get rid of all of True's old toys during a FaceTime call.

He said: ''What happens if we have another girl? We have to buy it all over again.''

Khloe, 35, said: ''Who is having another girl with you?''

Tristan insisted: ''Listen, I'm just saying, True does need a sibling.''

The 'Revenge Body' host then insisted she wouldn't be trying to conceive a child with the 29-year-old sportsman in the traditional way.

She said: ''I might get some embryos and get a sibling. I might need to borrow some sperm or get some from you...we'll figure that out later. That's a whole other episode.''

Khloe also admitted that ''co-parenting'' is very difficult.

She said: ''To co-parent is a different beast, it's probably the hardest thing I've ever had to figure out. Because, you get territorial. Like, 'This is my baby. Why are you telling me what to do?' You forget, oh no, it's both your baby.''