Heidi Klum receives a loving pat on the backside by husband Tom Kaulitz as they explore historic Venice together

Heidi Klum was having a blast exploring Venice, Italy with her husband Tom Kaulitz on Thursday. 

The model, 51, who previously put on a sexy display in the floating city, kept her look simple as enjoyed a shopping trip with her spouse, 34. 

The America's Got Talent judge kept cool in the 80 degree temperatures wearing a black strappy sundress with thin white vertical stripes, and a pair of brown slide sandals. 

The sexy frock featured a low back and the Making the Cut host seemed to be wearing a black bathing suit beneath it.  

During their outing, Klum's hubby of five years quietly reached over and patted her on the bottom. 

Heidi Klum, 51, looked relaxed as she enjoyed a shopping trip with husband Tom Kaulitz, 34, in Venice Thursday. The model, 51, kept cool in the 80 degree temperature wearing a black strappy sundress with thin white vertical stripes, and a pair of brown slide sandals

Heidi Klum, 51, looked relaxed as she enjoyed a shopping trip with husband Tom Kaulitz, 34, in Venice Thursday. The model, 51, kept cool in the 80 degree temperature wearing a black strappy sundress with thin white vertical stripes, and a pair of brown slide sandals

The runway veteran accessorized with a thick twisted gold chain with a large leaf-shaped medallion and gold earrings.

Klum wore a gold and platinum bracelet on her right arm and carried a small black purse.  

Her long blonde hair was styled straight and lay in loose layers. 

The cover model's makeup appeared natural with a neutral lip, and she wore large aviator style sunglasses. 

Kaulitz demonstrated his flair for fashion in a loose fitting black and white checked shirt and matching pants with black loafers. 

His shoulder length dark hair was in natural waves and his beard appeared a little bushy. The rocker carried a bag filled with purchases from Dolce & Gabbana. 

That same day Heidi shared video of her gondola ride with her husband. 

During their outing, Klum's husband of five years quietly reached over and patted her on the bottom

During their outing, Klum's husband of five years quietly reached over and patted her on the bottom

Klum shared a quick video of their ride through Venice as she canoodled with her spouse, writing 'VENICE' next to the post

Klum shared a quick video of their ride through Venice as she canoodled with her spouse, writing 'VENICE' next to the post

The trip seems to be part of a belated birthday gift for Klum, who turned 51 June 1

The trip seems to be part of a belated birthday gift for Klum, who turned 51 June 1

Klum shared a quick clip of their ride through Venice as she canoodled with her spouse, writing 'VENICE' next to the post.

The trip seems to have been part of a belated birthday gift for Klum.  She turned 51 June 1. 

Highlights included a trip to Paris for Klum and her hubby.

Heidi's brother-in-law Bill Kaulitz also gifted her with a ride on the Venice Simplon-Orient-Express.

The vintage train provides a luxurious trip for those who want to enjoy a glamorous experience in vintage style. 'Thank you @billkaulitz for the most beautiful birthday gift. We finally went !!!! Yippiiiiii,' she wrote next to the post.