Puppy love! Nick Kyrgios and his girlfriend Costeen Hatzi are greeted by their pet pooch at Sydney Airport after jetting into Australia

Aussie tennis star Nick Kyrgios and his girlfriend Costeen Hatzi jetted into Sydney Airport on Saturday.

The couple looked in high spirits as they were greeted by their nearest and dearest – including their pet pooch Boo who was waiting for them at arrivals.

Nick, 28, and Costeen, 23, beamed with joy as they patted the dog after greeting an awaiting family member.

The tennis star dressed casually in blue shorts and a black jumper as he pushed the couple's luggage through the airport.

He completed his look with a grey cap and wore white sneakers for his flight.

Meanwhile, Costeen dressed for comfort in a grey jumper, black tights and a pair of orange slides.

Nick and Costeen welcomed their pet puppy in August last year.

Costeen took to Instagram at the time to share a photo while holding the pampered pooch in the car as Nick sat beside her.

‘My family,' she wrote.

In April last year Costeen appeared on The Morning Show and spoke about her relationship with Nick.

She said she was a bit ‘sceptical' of the tennis star at first, after hearing about his ‘on-court reputation' through the media, but said she was pleasantly surprised when they first met.

‘I didn't really follow tennis but I would hear media when they spoke, not badly about him, but his on court behaviour, so I was a bit sceptical, but it was completely fine,' she said.

‘He's really supportive and I'm really lucky to have him,' she added.