Ashton Kutcher and Mila Kunis caught on Kiss Cam

Mila Kunis and Ashton Kutcher on the Kiss Cam (c) Los Angeles Clippers Twitter [Photo/Agencies]

The newly engaged couple put on a rare public display of affection during a basketball match on Saturday when their image was projected up on the big screen for the whole crowd to see.

Mila, 30, looked mortified and covered her face in her hands when she realised the Kiss Cam was lingering on them, but Ashton took the incident in his stride.

The 'Jobs' actor jokingly played up to the cameras, twisting his baseball cap around to one side before leaning over and confidently planting a smooch on his fiancée's lips.

The lovebirds' kiss drew appreciative cheers from the crowd as a blushing Mila pulled away, giggling.

The former 'That 70s Show' co-stars have been together since April 2012 and sparked speculation they were engaged earlier this month after the brunette beauty was pictured with a diamond sparkler on her ring finger.

Mila and Ashton are famously low-key about their romance and avoid talking about it in the press, spending most of their time at sporting events or family gatherings.

However, they have been more open in expressing their love since Ashton's divorce from Demi Moore was finalised.