Jennifer Lopez wants baby with Casper Smart?

Actress-singer Jennifer Lopez reportedly wants to have a baby with boyfriend Casper Smart.

The 43-year-old singer, who has five-year-old twins Emme and Maximilian with ex-husband Marc Anthony, is said to have taken to fertility treatments in the hope of getting pregnant with the 25-year-old, reports femalefirst.co.uk.

A source said: "She's scared that time isn't on her side with regard to her age. But she's hoping that with fertility treatments, she'll be pregnant in the next couple of months."

The couple reportedly put their marriage plans on hold because they couldn't reach a prenuptial agreement, and are now focused on having a baby.

"They argued constantly over it, but Jennifer has decided to let the issue go and put her trust in him. She's more interested in trying for a baby than planning a wedding right now anyway - and Casper is completely on board," the source added.

The singer wants to keep the treatments a secret and Smart has agreed that they will both act surprised when they make the announcement of her pregnancy.

The source said: "She's paranoid about people knowing about her pregnancy hardships, because it makes her feel old."

"He loves Jennifer and he knows he's set financially for life if she has his baby. They made a deal that when the pregnancy happens, Jennifer will make it sound like an 'oops' and a blessing at the same time, even though she's actually planned the whole thing," the source added.