Despite rumours of their 'mind-blowing' romance, they appeared separately when attending the Formula E Hong Kong E-Prix at the Central Harbourfront Circuit on Sunday morning.
But behind the scenes, Naomi Campbell, 48, and Liam Payne, 25, reportedly couldn't take their hands off one another, acting 'like giggly love struck teenagers' when away from the cameras.
The pair - who were first publicly spotted together in January - also dined together for lunch at a VIP event at the BOSS | EMOTION Club, The Sun reported.
Together again: Naomi Campbell, 48, and Liam Payne, 25, did little to quash relationship rumours once again as they attended the Formula E Hong Kong E-Prix on Sunday
They also enjoyed a private garage tour, where they reportedly made it clear they weren't to be photographed together.
A source told the publication: 'Naomi and Liam were acting like love struck teenagers on their first foreign holiday when they were out of the public's gaze.
'She is very tactile and Liam made sure he poured compliments on her as they spent time together at the event.
'Love struck teenagers': Behind the scenes, the couple reportedly couldn't take their hands off one another, acting 'like giggly love struck teenagers' when away from the cameras
'They were all over each other at times and were both very giggly. But when the formalities started, including pictures with the organisers and sponsors, they split off and would not be seen together.'
And while the couple both shared pictures and videos from the event to social media, they refused to mention that they were together at the occasion.
Dressing to impress, Naomi displayed her flair for fashion during the outing as she rocked an edgy denim jacket, embellished with structured puffball sleeves.
Looking good: Upping the style ante, Naomi teamed her outerwear with a pair of wide-leg trousers and a plunging black cami (pictured with Brazilian racing driver Nelson Piquet Jr.)
Catching the eye: The supermodel displayed her flair for fashion during the outing as she rocked an edgy denim jacket, embellished with structured puffball sleeves
Upping the style ante, the catwalk queen teamed her outerwear with a pair of wide-leg trousers and a plunging black cami.
The South London beauty maintained her striking display in the footwear department as she boosted her frame in a pair of suede peep-toe boots.
Naomi turned heads with her quirky choice of accessories as she sported octagon-framed sunglasses and a selection of silver rings.
With her poker straight tresses worn in a half up half down style, the Vogue coverstar complemented her youthful-looking appearance with heavy strokes of neutral-toned make-up.
All in the details: The South London beauty maintained her striking display in the footwear department as she boosted her frame in a pair of suede peep-toe boots (pictured with Belgian racing driver Jerome d'Ambrosio)
Meanwhile, former One Direction star Liam looked effortlessly cool as he sported a black bomber jacket, navy jeans and a snug T-shirt.
The rumoured couple proved to be in their
