Jennifer Lopez loves how Casper Smart treats her children.

The 43-year-old singer recently celebrated her first anniversary with her backing dancer, 25, and friends say the relationship got serious when Jennifer realised how good he was with her four-year-old twins Max and Emme.

A source said: ''One of the things that made Jennifer fall in love with Casper is how good he is with Max and Emme. He spoils the kids almost as much as he spoils Jen. Last week he bought them a roll out piano they can walk on. They flipped out.

''Jennifer loves that he is a really open and honest guy and they really connect emotionally. Plus he stands up to her.''

Although Jennifer's family and friends tired to warn her off Casper, she is serious about him and is looking towards the future.

The insider added: ''Jennifer is so excited to have made it to the one year mark, not only because she's so in love with Casper but because she kind of feels like it's them against everyone else.

''They've taken such a beating from family and friends because he's so young. It felt like everyone was trying to split them up for the longest time but they stuck it out.''