Casper Smart has proposed to Jennifer Lopez ''five times this year''.

The 'On The Floor' hitmaker is reportedly fuming with her on/off boyfriend as she is ''sick'' of constantly saying 'no' to his proposals.

A source told Life & Style magazine: ''Jen finally snapped at Casper by ordering him to stop proposing because she's sick and tired of saying no.

''He's probably asked her at least five times this year alone!''

Meanwhile, an insider previously claimed that Jennifer - who has seven-year-old twins Max and Emme from a previous relationship - is always spending time with Casper.

They said: ''Jennifer and Casper just get each other. They have a wonderful working relationship and a wonderful real relationship! Plus, her kids love him.

''Jen and Casper spend all their free time with each other. He is always at 'American Idol' with her. They work together as well, so time together is plentiful. They like being with each other and find a lot of time to hang out with each other.''