Jessica Simpson cried more than her son after he broke his arm.

The 37-year-old singer and actress' four-year-old son Ace broke a bone in his left arm, which left her in tears, and she shared a photograph of the youngster in what appears to be a doctor's office, sporting a bright green plaster cast on his left forearm and elbow.

Jessica captioned the snap: ''This kid is breaking more than hearts these days #FirstBrokenBone #ICriedMoreThanHeDid #ACEKNUTE (sic)''

The 'With You' hitmaker - who also has a six-year-old daughter Maxwell with her husband, former American football player Eric Johnson - attended Ace's kindergarten graduation ceremony with him last week, and she recently gushed about how proud she is of her children.

Speaking at the 40th Annual Outstanding Mother Awards in New York last month, the 'Dukes of Hazzard' star said: ''The most rewarding part of being a mother is really just watching my kids grow. It's like, how much knowledge they have about life is just so meaningful to me, and how much heart they put into everything they do.

''There's just nothing like the innocence of a child.''

But the blonde beauty is not tempted to have any more kids.

Last year, Jessica revealed she's had an intrauterine device (IUD) fitted as a form of long-term birth control.

She said: ''I'm not pregnant. We got an IUD, nothing's gonna get in that uterus.

''I have two beautiful children, and I'm not having a third. They're too cute ... you can't top that.''