Jennifer Lopez spends American Idol commercial breaks 'affectionately rubbing' her beau's head.

The singer is one of the judges on the singing contest, alongside Steven Tyler and Randy Jackson.

Her 24-year-old boyfriend Casper Smart is always in the audience to support the 42-year-old star and can't help racing up to see her when adverts are being shown to the viewers at home.

'It's obvious to everyone that Jen is gaga over Casper,' a source told National Enquirer. 'They spend the break looking adoringly into each other's eyes, and Jennifer affectionately rubs his close-shaved head.'

Casper usually brings Jennifer a drink and also hands over her phone so she can check for messages or voicemails.

Workers on the show have noticed how relaxed the megastar singer seems nowadays.

'She's friendly, smiling, and even joking with the show's staff,' one said.

Jennifer began dating backing dancer Casper following the breakdown of her marriage to Marc Anthony.