Is it ever OK to boo sports stars?

Darts crowds are famous for being noisy.

Fans sing, cheer and sometimes boo the players on stage.

But world champion Luke Littler says some crowds have gone too far with their booing, and one darts expert fears the 19-year-old could eventually walk away from the sport.

But is it ever OK to boo a sports star? Is it unfair and rude or just part of the fun?

Take part in the vote below, and have your say in the comments.

A pantomime-style atmosphere - and even dressing up - is part of the darts experience in lots of places, and crowds are known for being noisy.

But Luke Littler has been complaining after he faced super-loud booing and whistling during the World Series of Darts Finals in Amsterdam in the Netherlands.

The noise became so distracting during his match against Nathan Aspinall that the referee had to stop play and ask the crowd not to whistle while the players were throwing.

Littler had also been booed while beating Dutch favourite Danny Noppert the previous day. "There's just no point in me travelling, wasting my time whilst I'm getting booed," Littler said.

Littler has faced similar treatment in Germany and has stopped playing in European Tour events in the country.

"If the Dutch stay like this, then I'm not going to do any Euro tours over there," Littler said. "I just want to play my darts, obviously sign autographs.

"The past two nights, I've done nothing, I've just walked off stage and not thanked anyone.

"There's no point thanking everyone when they are booing me."

There probably isn't one simple reason. Some Dutch supporters may have wanted their home players to win.

In the UK, Luke's support for Manchester United has sometimes created a playful rivalry with crowds in places such as Liverpool and Leeds.

At one competition, Littler also made a "cry baby" gesture towards the crowd following a tense match against Dutch player Gian van Veen.

Van Veen called Littler a "bad loser" and said he was "out of order" but Luke said his reaction was meant for family in the crowd, not to taunt Van Veen,

But moments like that might have changed how some supporters react to him.

BBC Sport's Nesta McGregor says: "He is a multi-millionaire with lucrative sponsorship deals and his own TV show. But has his rapid rise turned some against him?"

Luke Littler is also one of the world's best players and wins lots of trophies, so some fans may simply want to see somebody else do well.

After he was booed at the PDC World Championship in London Littler said: "I'm not bothered [by the booing]. Really not bothered. You guys pay for tickets and you pay for my prize so thanks for booing me."

But could the booing make Luke Littler give up darts all together? Samuel Gill, editor of Dartnews.com, worries it could.

Speaking to BBC Sport he said: "There's a real fear that within a few years he'll just turn around and walk away from the sport.

So, what do you think? Is booing Luke Littler harmless sporting fun, or should crowds show him more respect?