Hills star Kristin Cavallari grabs hold of her friend for support as she watches tense football game

It was a tense bit of television for Kristin Cavallari.

Watching the game on TV at a West Hollywood bar on Sunday, The Hills star could hardly stand to look.

The reason for her worry? She was watching rumoured American football star boyfriend, Chicago Bears player Jay Cutler lose to the New England Patriots.

Horseplay: Kristin grabs her friend's backside as they watch a game onscreen at a sports bar

Horseplay: Kristin grabs her friend's backside as they watch a game onscreen at a sports bar

Wearing a team-supporting T-shirt and a cute pair of white denim cut-offs with sandals, Kristin was so worked up she even grabbed her friend's bum at one point.

The 23 year-old reality star dealt with the tension by smoking a cigarette and joking with friends at the bar.

But it wasn't a total loss.

Kristin made a comeback that night by dressing up to the nines for a fancy dinner at celebrity hangout Boa Steakhouse.

Casual cool: Kristin Cavallari enjoyed a relaxing afternoon watching sports before later dressing up for a night on the town

Casual cool: Kristin Cavallari enjoyed a relaxing afternoon watching sports before later dressing up for a night on the town Sunday

Accompanied by a bevy of girlfriends, Kristin wore a little black dress with a deep plunging neckline and nude-coloured patent heels.

Her friends followed suit - literally.

The girls all wore mini black dresses and carried clutch bags, just like Kristin.

The blonde starlet herself looked to be in a much better mood after the reviving dinner outing, smiling as she made her way to her car.

Kristin and Jay were first spotted together making out at the Angels and Kings lounge in Chicago in late August.

Dolled up: Kristin and her girlfriends dressed that night for a dinner at posh eatery Boa Steakhouse in West Hollywood

Dolled up: Kristin and her girlfriends dressed that night for a dinner at posh eatery Boa Steakhouse in West Hollywood

However Jay initially denied reports of dating, telling Chicago's Sun-Times, 'I find it kind of funny.'

'That stuff, you have to laugh about it,' he added. 'I had dinner with her and that was pretty much about it.'

Meanwhile, it's a busy time for Kristin.

The actress, who finished filming on her show The Hills at the end of August, has a slew of new projects in the works.

She's going to try her hand at design, working on a new shoe range, and she has three new reality TV projects that she's producing.

Ladies night: Kristin and the girls all wore matching little black dresses

Ladies night: Kristin and the girls all wore matching little black dresses