Britney Spears' ex-husband Kevin Federline is 'really happy' that the star is engaged.

Britney accepted Jason Trawick's marriage proposal over a romantic dinner on Thursday night. The pop songstress had a famously tumultuous relationship with Kevin, but he is thrilled that Britney is settling down with Jason.

'I'm really happy for her - I think he's a great guy,' he told Australia's TV WEEK magazine.

'She's happy; she's doing really well. I want to say she's in a good place. I haven't spoken to her much since I've been over here, both of us have been busy with her being on tour, but I do know from talking to the kids and talking to the kids' teachers that they're doing really good.

'It's a good step in the right direction. I'm totally happy for her.'

Britney and Kevin had two sons ' six-year-old Sean and Jayden, five ' before their divorce was finalised in 2007.

Kevin is happy that Jason has become a reliable step-dad to his children with Britney.

'He's a really good guy, I've heard a lot about him,' he revealed. 'I've spoken to him quite a few times as of now. He seems like a really good guy. The kids speak highly of him [and] her family loves him.'

Britney had a very public breakdown in 2007. Kevin has recalled the dark times in the songstress' life, which saw her lose custody of her two young boys.

'It was tough. [They were] just very, very, very dramatic times. I had to do what I had to do for the safety of our children. But at the same time, it tears my heart to pieces to watch your ex go through that, let alone watch anybody go through that,' he admitted.

'It's horrible. It was a completely dramatic, depressing stage of my life that I'm so glad I'm over and get to leave behind. It was tough.'

Meanwhile, details of Britney's new engagement ring have emerged.

The 40-year-old agent enlisted the help of Neil Lane, who designed the stunning piece of jewellery.

'Jason is a romantic and when I asked him to tell me about Britney and what the ring would represent to them so I could find inspiration, his response was always the same - she is his princess!' he told People.

Neil designed the ring from scratch. It boasts a 'round, perfect white diamond in a handmade platinum setting that looks like a mini crown,' he described.

He also added 90 small round diamonds around the eternity band.

'Jason didn't want an over-the-top ring with a giant stone,' he added.

This will be the third time Britney has tied the knot.

Aside from her marriage to Kevin, the 30-year-old also had a 55-hour union to childhood sweetheart Jason Alexander.

It was annulled in 2004 after the pair wed in Las Vegas.