Marc Anthony believes Casper Smart 'fulfills a very important role' in the family.

The singer shares twins Max and Emme with ex-wife Jennifer Lopez, who has been in a relationship with dancer Casper since October 2011.

Marc shocked fans by gushing over how awesome Casper is during his appearance on The Wendy Williams Show earlier this week, but the star thinks it's imperative he be friends with his former spouse's new partner.

'I don't know what they expect, but Jennifer and I have a responsibility to the kids and so does Casper,' he told Extra. 'He fulfills a very, very important role. My children love him and respect him and so do I. I get it, he gets it, we get it. we really bonded. He's a really good guy, solid guy,' he explained before joking: 'Until he f**ks it up, that's my story!'

Marc has exciting plans for the twins' sixth birthday, which lands on February 22.

The musician is putting on a massive party, as he is determined to give his children a day to remember.

'We have a big one. It's at this place that we rented out with trampolines and all that good stuff,' he said.

Marc and Jennifer split in 2011 but he has made it clear she will always be a very important part of his life.

"I'll always love Jennifer," he told ABC News around the time of the breakup.

'She knows that. Jennifer's a wonderful, wonderful woman, a wonderful mother, a wonderful friend, you know. We understand this to be a long story. This is not a short story."

Despite having two failed marriages behind him, Marc still believes in love. He is convinced there is still someone special out there for him.

"I do. I believe in relationships. I believe that God has blessed me in so many ways. Material things go but so far. Success goes but so far. But when your house is empty and you don't have someone to invest in, if you don't have a witness, it's almost worthless,' he said on The Wendy Williams Show.