Tennis is back on our TVs and so, dear reader, is the long-running tennis feud between Nick Kyrgios and Novak Djokovic.

Insults are being thrown, surprise midnight commentary has been sprayed, and we're now at a point where the Australian and Serbian are just going tit for tat as the Australian Open gets underway in Melbourne.

The two tennis stars have only actually played each other twice on the court, in back-to-back tournaments in 2017. Kyrgios won both games.

Watch: On Monday, Kyrgios responded to Djokovic's recent comments about him. Post continues after video.

To understand the tension, let's go back to the start. Becauseboy, a lot has happened since 2019.

It all began with a podcast.

Kyrgios appeared on theNo Challenges Remainingpodcast in May 2019, where he said: "I just feel like he [Djokovic] has a sick obsession, wanting to be liked. He just wants to be like Roger [Federer]. He just wants to be liked so much that I just can’t stand him."

"This whole celebration thing (blowing kisses to the crowd) that he does after matches, it’s like so cringeworthy. It’s very cringeworthy," Kyrgios continued.

The men's world no. 1 initially opted to take the high road when he was inundated with questions relating to Nick Kyrgios’ podcast taunts.

Publicly Djokovic said he "wasn't losing sleep" over the claims, but eagle-eyed fans spotted the Serb 'liking' an Instagram post, which quoted John McEnroe from a BBC Radio interview saying about Kyrgios: "I don’t think he should be out there anymore unless he gives an honest effort."

In June 2019, he told Sportsklub, "What can I say to Nick Kyrgios. I really think he's not really a bad guy. I do not know why he declares all these things, whether he wants to draw attention or some motive is different."

The following month, after being eliminated from Wimbledon, the Australian sent out a subtle jab ahead of Djokovic's match with Roger Federer, tweeting: "Federer please win."

Federer please win 👻

— Nicholas Kyrgios (@NickKyrgios)

Then footage started doing the rounds on the internet of Kyrgios signing his name over a fan's 'Novak' t-shirt during the Atlanta Open, telling the camera "that's what I think of you" after crossing out Djokovic's name.

In August 2019, Djokovic exploded at the crowd during the US Open, telling them to "shut the f**k up" as he tried to concentrate during a practice session.

After an inaudible, but heated discussion with a fan the Serbian said, "I’ll come find you after the match. Trust me, I’ll come find you," and of course, Kyrgios couldn't help but comment.

"I'm scared," the Australian wrote on Twitter.

I’m scared 🤣

— Nicholas Kyrgios (@NickKyrgios)

In September 2019, Djokovic's coach Goran Ivanisevic weighed in, telling the Telegraph,"It’s bad because I don’t think Novak did anything wrong to him. He decides to pick on Novak for no reason. You can come on the court and do whatever you want, but you need to respect your opponent."

"He speaks a lot about Novak, only he knows the reason. But he should just take care of himself because he should be in the top five, he could win a Grand Slam. He’s never going to win a Grand Slam with the approach he has now," he added.

In January 2020, Kyrgios was spotted in the stands at midnight watching Djokovic play doubles at the ATP Cup - reportedly openly barracking against the Serbian star and sniggering at his every mistake.

Kyrgios enjoying the tennis https://t.co/dY3IAfCoqc

— José Morgado (@josemorgado)

When asked if he was disappointed with Kyrgios' late-night visit, a diplomatic Djokovic said: "To be honest, not really. I didn't see him in the stands but then I saw the videos after that [on social media]. I know he's a good buddy with (France's Gael) Monfils and with the French team, so, you know, it's fine."

He did, however, have an ever so slight dig by adding: "And Kyrgios knows how to have fun and how to attract attention, that's for sure."

Later that month, Kyrgios posted on Instagram with American tennis player Tennys Sandgren alongside the caption: "Tennys and I love Novak," which he later deleted.

It made headlines nonetheless as another little swipe to add to the 'feud' tally board.

Nick Kyrgios et Tennys Sandgren ensemble sur une même photo : diable, l'évidence même ! Mon court portrait de Sandgren 👉 https://t.co/ckOPedbvsK #AusOpen pic.twitter.com/sq0B82V504

— Service Volée (@SVolee)

In April 2020, Kyrgios downed about six glasses of wine and took part in an Instagram live with fellow Aussie tennis player Thanasi Kokkinakis and actually said something sort of nice about his rival.

"I don't actually hate anyone. I can admit that people are different. I don't like some of the things he [Djokovic] does but I don't hate him," he said.

But the niceties didn't last long, because in June 2020, Djokovic spearheaded the disastrous Adria Tour and Kyrgios did not hold back.

From the beginning, the tour was dogged by criticism for even attempting to go ahead in the middle of the global pandemic, but the outrage only escalated when it was clear no one was following COVID safe guidelines.

Kids stood shoulder to shoulder during the opening ceremony, players hugged post-match just like they used to, and there was barely a mask in sight.

Opening ceremony at the Adria Tour in Belgrade. Social distancing: nonexistent. At least some wear masks, sort of. pic.twitter.com/QQyzBtljNG

— Del🇪🇺 (@Stroppa_Del)

"We have different circumstances and measures, so it’s very difficult to think of international standards," Djokovic said at the time.

"You can also criticise us and say this is maybe dangerous, but it’s not up to me to make the calls about what is right or wrong for health," he continued.

Then tennis players started testing positive, including Djokovic. Kyrgios was ready and waiting to lead the tennis world's condemnation of the entire event labelling it a "boneheaded decision."

When footage emerged of Djokovic dancing shirtless with several players during the Adria Tour, Kyrgios wrote on Twitter: "Prayers up to all the players that have contracted COVID-19. Don’t @ me for anything I’ve done that has been ‘irresponsible’ or classified as ‘stupidity’ - this takes the cake."

Prayers up to all the players that have contracted Covid - 19. Don’t @ me for anything I’ve done that has been ‘irresponsible’ or classified as ‘stupidity’ - this takes the cake. https://t.co/lVligELgID

— Nicholas Kyrgios (@NickKyrgios)

When Austria's Dominic Thiem defended Djokovic against Kyrgios's criticism, accusing the Australian of "a lot of mistakes himself", Kyrgios didn't hold back.

“What are you talking about, Dominic Thiem? Mistakes like smashing rackets? Swearing? Tanking a few matches here or there? Which everyone does?” said Kyrgios

"None of you have the intellectual level to even understand where I’m coming from. I’m trying to hold them accountable.

"This just shows what a joke Dominic Thiem, Alexander Zverev, and Novak Djokovic think this is. Two of them partying like potato’s (sic) during a global pandemic. People losing lives, loved ones and friends, and then Thiem standing up for the ‘mistake’.

"These guys are the ‘top’ of our sport. SMH [shaking my head]."

Djokovic defended himself against all his critics, telling Serbia's daily Sportski Zurnal they had entered into a "witch-hunt".

Kyrgios responded by posting a video of him winning a point (during a match he won) against the Serbian, with lyrics from the song ‘Mocking It’: “Talk sh*t but I’m doing what I do, you wouldn’t last if I put you in my shoes”.

In August 2020, Djokovic told the