Kelly Osbourne had the "biggest fight" with her boyfriend Sid Wilson over their son's name.

'The Osbournes' star and the Slipknot rocker are parents to a little boy named Sidney - who was born in 2022 - and Kelly, 39, has now revealed the pair fell out after disagreeing on whether the youngster should take both of their names with Kelly eventually relenting and letting her partner have his way.

During an episode of 'The Osbournes Podcast', she explained: "This is personal, and I didn’t expect to ever talk about this, but I’m going to. It’s the biggest fight me and my baby’s father have ever ever ever had, and probably ever ever will.

"I wanted our son to have both of our last names, and he wouldn’t let me. We had a huge fight. I feel that I was forced into doing something I didn’t wanna do and I can never ever ever forgive him for that, but we can move on."

Kelly went on to insist she never felt right about Sidney only having his dad's last name, so they continued to talk about the issue and went to couple's therapy in a bid to reach a resolution - and they have now agreed to legally change their son's name to make it double-barrelled.

She added: "So right now my son doesn’t have a double-barrelled last name, but after lots of eye-opening conversations and some couples therapy, he [Sid] has seen the light. We are going to legally change our son’s name to have both of our last names ...

"We both made our child, so he should have both of our last names".

After her revelation, Kelly's dad Ozzy Osbourne weighed in on the matter and insisted Sidney will benefit from the famous family name, saying: "Well, it’s in his favour."

It comes after Kelly declared becoming a mum has given her a "purpose in life".

The former 'Fashion Police' host insisted she had no "adjustment period" as she settled into parenthood because she has willingly embraced all aspects of having a child.

She told 'Entertainment Tonight': "Mom life is the absolute best. There was no adjustment period for me because I love it all. The good, the bad, the ugly, I take it all. It's so much fun.

"It's given me a purpose in life like nothing ever has. Just getting to watch my little man grow and seeing him become a little person is just, like, it's gonna make me cry if I keep talking about it."