Brutal moment cage fighter proposes to his girlfriend just after losing a fight and she says NO - then makes a shocking claim about their romance

An MMA fighter has been left humiliated in front of 20,000 fans after he proposed to his girlfriend after losing a fight - only to have her turn him down and accuse him of cheating on her.

The awkward incident, filmed last weekend at the Clash of the Stars tournament in the Czech Republic, shows Czech fighter Lukas Bukovaz down on one knee making the proposal after being defeated in his bout.

In a sign bad news was on the way, the woman held her hand up to her face in embarrassment as the crowd cheered.

'Based on everything that's happened, I think probably not,' she said into the microphone.

'I don't think so.' 

Czech fighter Lukas Bukovaz proposed to his girlfriend after losing his MMA bout last weekend (pictured) - and didn't get the result he was hoping for

Booing then erupted from the crowd and a man at ringside was seen trying to throw water on the woman.

Bukovaz's girlfriend then went on to explain to the 20,000 fight fans that he had cheated on her with another woman.

In a clip later posted to his Instagram account, Bukovaz denied the accusation that he'd been unfaithful.

Social media users have expressed sympathy for the MMA fighter since his very public embarrassment went viral online.

'Talk about taking the double L. Sorry for the guy,' posted one fan on X.

'2 losses in 2 mins. Rough for broski,' replied another.

'That is a bad night in anyone's book,' said a third.

The girlfriend knocked back the fighter's marriage proposal in cringeworthy scenes - then alleged that Bukovaz had cheated on her with another woman

Bukovaz - pictured in a previous fight - had dyed his hair pink before popping the question

The Czech fighter (pictured) lost the bout before the proposal despite being teamed up with another fighter in a two-on-one contest that they would've been widely expected to win

Other fans suggested that Bukovaz could have timed his proposal better.

'Know when to pick a moment,' one wrote.  

'He could have saved it til he won a fight. Someone should have taught this guy about timing.'

To make matters even more embarrassing for Bukovaz, the bout he lost featured him and another fighter, Patrik Horvath, teaming up to take on Jan Michalek in a two-on-one contest that they would have been widely expected to win.