United Kingdom, Sept. 30 -- Jerry Hall finds it "easy" to be friends with Sir Mick Jagger.

The 70-year-old supermodel - who has four children with the Rolling Stones rocker, who she split from in 1999 after 22 years together - spends a lot of time with her ex-husband and his current partner Melanie Hamrick because they are good company and a "lot of fun".

She told Grazia magazine: "I think you should always try to be friends with people you have children with. It's really important, because that's forever.

"Mick's easy to be friends with because I really like him - he's a lot of fun and a great dad. I like his partner, Mel. They come out quite often to my house, and we have such a good time.

"Mostly, we play games: backgammon, chess, ...