This is the shocking moment a couple's trip to a cellphone store turned into a violent affair when the boyfriend caught another man staring at his girlfriend's bottom. 

The couple was visiting the SEA Wireless shop in Lincolnton, North Carolina when the boyfriend caught the creepy customer's wandering eyes.

In a video filmed on the store's CCTV camera, the bystander, sporting a red shirt and cap, gives the boyfriend and sleazy smile and says 'Yeah'.

When the bystander says 'Bye!' the offended boyfriend charges towards him and punches him square in the face as he tries to walk away. 

The boyfriend hits the man so hard that his cap flies off. 

After the brutal punch across the face, the bystander says 'What's your problem bro' then walks out the door.  

The shocking incident unfolded on August 8.

While the boyfriend and bystander were getting heated, the girlfriend simply slapped her hands to her side as if frustrated and embarassed with her protective boyfriend. 

She yells her boyfriend's name then shouts 'What is wrong with you'.

Then she pleads with the seemingly un-bothered store clerk to not call the cops. 

'You need to go say sorry, please,' she says to him and he obeys, promptly walking outside.