In a photo shared with her 158,000 followers, the mother-of-two could be seen showcasing a colourful short-sleeved mini dress whilst cuddled up to Rod, who leaned his head on her shoulders whilst smiling at the camera.
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Penny looked gorgeous, as usual, with her long blonde locks styled in soft waves, whilst keeping her makeup natural.
The couple, who recently celebrated their 16th wedding anniversary, were at The Peninsula New York, a five-star hotel located right next to the MoMa, and had two pink cocktails beside them. It was no doubt a night to remember, judging by Penny's caption.
The couple were joined by various family members
"@salondeningmanila on a very hot, sultry night in New York," she wrote alongside it.
Friends and fans loved the update, with one noting: "What a lovely photo." A second wrote: "What a stunning picture of Penny Lancaster and Sir Rod Stewart the best couple on the planet I love and adore," whilst a third added: "Still new to these socials. Love how adorable and authentic you two are."
Penny's niece Raphaella joined the family in New York earlier this week
Penny later shared more snaps of their fun day in the city, and it showed that the couple had then headed to another NY hotspot, The Ned NoMad's rooftop terrace, and were accompanied by their son, Alastair, 16, Rod's son Sean, 41, and Penny's niece, Raphaella.
Earlier this week, Penny announced that her niece had joined them in the Big Apple, and for her first night in the city, Penny and Rod treated her to an incredible dinner at the most exclusive fine dining American restaurant on the water in NYC, The River Café.
Penny and Rod have been showing the Big Apple to Raphaella
Later in the week, Penny took her to the Edge, New York, a protruding 100-stories-high observation deck, with a glass floor, bar & 360-degree NYC views.