Jennifer Lopez has only been dating toyboy lover Casper Smart for a short while but she is apparently already talking about making him her fourth husband.

The 42-year-old singer ended her relationship with estranged husband Marc Anthony back in July after seven years of marriage.

But Star magazine is reporting that Jennifer is planning on tying the knot with the 24-year-old backup dancer as soon as the ink is dry on her divorce papers.

'Jennifer never does anything half-way, especially relationships,' a source told the publication. 'This thing with Casper is no different. She told him that as soon as the divorce goes through, she wants to run away with him and get married.'

But the Jenny From the Block singer's family are apparently horrified by the prospect and her mother Guadalupe is worried by her daughter's increasingly impulsive behaviour.

'Guadalupe thinks Jennifer has lost her mind,' the insider added. 'She's outraged that Jennifer is giving Casper an allowance and showering him with gifts. Both Guadalupe and J.Lo's younger sister, Lynda, are begging her to take a step back, if only for the sake of [her three-year-old twins] Max and Emme.'

And Jennifer's ex Marc is also said to be none too pleased about the new man in Jennifer's life and apparently exploded when he saw pictures of Casper playing with his children during their trip to Hawaii over the Thanksgiving holiday.

'Marc is still close with Guadalupe, and he just about lost it when she told him that Jennifer wants to remarry,' the source said. 'He thinks she's making a fool of herself.'

'He told her that he'd fight her for sole custody of the kids if she pulled some crazy stunt like running away and eloping.'

But the lovestruck American Idol judge is said to be determined to prove her critics wrong and doesn't care what anyone thinks of her romance with the man 18 years her junior.

'J.Lo says Casper is the first guy who really gets her and that he's great with Max and Emme,' the source said. 'The more people interfere, the more adamant she becomes about tying the knot with Casper.'