Lamar Odom. Picture: Bang Showbiz

Lamar Odom's son has slammed the former sportsman for not telling his family about his engagement to Sabrina Parr until they saw the news on Instagram.

The 40-year-old retired basketball player announced on Instagram on Monday that he was to marry Sabrina Parr after four months of dating and the news came as a shock to his 17-year-old son, Lamar Jr., who had no idea.

And the teenager, who has a 21-year-old sister, Destiny, admitted Lamar's family "don't approve" of his dad's new partner.

He ranted in a now-deleted Instagram comment: "Not a [text] or phone call to see how people who've known this dude his whole life, to see how we would feel or react.

"Knew shawty for 4 months and already got you twisted, fam n friends already don't approve of homegirl but she already got your ass in a sunken place.

"Shame family gotta find out on social media but that's been how life been all the time as a son of an odom.(sic)"

But on Tuesday, Lamar Jr. admitted he went too far with his comment but admitted he was frustrated at being kept out of key moments in his dad's life.

He wrote: "Last night I was emotional seeing my father got engaged through social media.

"I was hurt and caught off guard. At the end of the day, I am a teenager, that is becoming a young man. I have to be responsible for what I post, I have nothing but love for my dad and want what's best for him."

Lamar - who was previously married to Khloe Kardashian and his kids' mother, Lisa Morales - revealed on Instagram he had popped the question during a romantic dinner at Prime 112 Restaurant in Miami, Florida.

The former "Dancing With the Stars" contestant shared a photo of himself and Sabrina - who showed off her huge pear-cut diamond engagement ring - at the restaurant on his Instagram account and captioned the picture: "Introducing my new fiancée!! Soon to be Mrs. Parr-Odom. She the ONE!!!!! @getuptoparr.(sic)"

The 32-year-old life coach also shared the news on her own account, showing followers a series of videos of her new jewellery.

She captioned her post: "I SAID YES!!!![ring and bride emojis]@lamarodom #mrsparrodom #lamarandsabrina (sic)"