Tennis Star Madison Keys' Fiancé Caught Picking Nose at Wimbledon

Madison Keys' fiancé found himself in a pick-le ... 'cause ESPN jumped to him at the wrong time -- and, they caught him fingertip deep in his nostril.

The American tennis star was in the third set of her round of 16 match against Italian player Jasmine Paolini Sunday when ESPN's broadcast flashed over to her coach and fiancé, Bjorn Fratangelo.

Check out the clip ... Bjorn's hanging out and chatting with a woman to his right, when he brings his fingers up to his nose and decides to drag out a bothersome boogie.

He's going at it for a while ... clearly trying to get a grip on whatever's irking him -- and, for some reason, ESPN decides to stay on the guy instead of cutting away.

The moment goes on for so long, one of the announcers breaks out into laughter and has to tell the camera operator to cut away from the poor man.

The reaction on X has been mixed, to say the least ... with some sharing their disgust while others are pointing out the dude's human -- and sometimes even the best of us have to pick!

Unfortunately, the match didn't end as humorously ... 'cause Keys had to retire from the match early after a leg injury limited her movement. She's out of the tournament now while Paolini has a date with Emma Navarro in the quarterfinal.