Smashing good body! Katharine McPhee parades her toned figure while celebrating birthday in Las Vegas

Katharine McPhee showed off her enviable body - and sense of humor - while celebrating her birthday in Las Vegas. 

The 31-year-old was clad in a blue and white striped bikini as she posed alongside her girlfriends and a male dressed as a female lifeguard in an Instagram snap shared on Saturday.

'Earlier today we sought out the hottest lifeguard around... Never seen a club at a pool. #classy #Vegas #belatedbdayweekend #hakkasan' she captioned the photo.

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Smashing good time! Katharine McPhee showed off her enviable body - and sense of humor - while celebrating her birthday in Las Vegas on Saturday

Smashing good time! Katharine McPhee showed off her enviable body - and sense of humor - while celebrating her birthday in Las Vegas on Saturday

Her brunette locks are pulled back and she concealed her eyes behind cat-eye sunglasses. 

The cheeky male companion had on a red one-piece swimsuit with large padded breasts. Making his look more convincing, he had on a blonde braided wig accessorized with red ribbons. 

One of Katharine's friends, who was dressed in a two-piece bikini, stroked the generous bosom during the comical photo.   

More tum! Rounding out the weekend-long soiree, the American Idol alum flashed more of her rock hard tum wearing a cropped grey top and red skirt at a nightclub where she was joined by her 31-year-old boyfriend Elyes Gabel

More tum! Rounding out the weekend-long soiree, the American Idol alum flashed more of her rock hard tum wearing a cropped grey top and red skirt at a nightclub where she was joined by her 31-year-old boyfriend Elyes Gabel

The Smash actress turned 31 years old on March 25 - but kicked off the party more than a week later at Hakkasan in Sin City. 

Rounding out the weekend-long soiree, the American Idol alum flashed more of her rock hard tum wearing a cropped grey top and red skirt at a nightclub where she was joined by her 31-year-old boyfriend Elyes Gabel. 

'Last night in vegas @cottrellguidry @living_ellestyle @indotjoy #omnia' she wrote.

Katharine and British hunk Elyes are co-stars on the CBS series Scorpion.

The beauty plays Paige Dineen, a single mother who helps to translate the 'real world' to a genius named Walter O'Brien, played by Elyes, who then helps her to understand her genius nine-year-old son.

Safety first.

A photo posted by Katharine McPhee (@katharinemcphee) on

The drama, which premiered last year in September, has been renewed for its second season.  

Meanwhile, the Over It singer recently revealed she had shelved her current musical project in favour of making the most of her acting opportunities.

She told the Los Angeles Times: 'My record got put on the back burner. It will take some figuring out as far as the music fits, some realigning.

'I'm letting the pieces fall where they may, letting the show settle a little bit.' 

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