Donnie Wahlberg Reveals His Dog and 'Constant Sidekick' Lumpy Died Earlier This Year

Donnie Wahlberg's dog Lumpy has died at the age of 12.

In a heartfelt caption on his Instagram Wednesday, the NKOTB singer revealed his "beloved dog" was laid to rest on May 18 but he avoided addressing the pooch's death publicly.

"So many of you asked me about my constant sidekick, Lumpy," the Blue Bloods actor wrote. "His usual playful presence, by my side, was clearly missed by all. Night after night, I uncomfortably avoided the conversation."

Whalberg, 52, said Francis "Lumpy" Wahlberg was so important to so many people, he did not confirm his death until now.

The singer said it was easier to focus on "joy, happiness and love" when Lumpy came up in conversations with fans on the tour. "Three things that we all needed so desperately after the last few years of sadness, heartache and struggle," he said in the caption.

"I know how much Lumpy meant to so many of you," Wahlberg wrote to fans. "He had become a special member of our Blockhead family. He was also a very special and beloved member of my family. His loss was a devastating blow to us all."

The post also featured a slideshow of images of the French bulldog with his humans, including Wahlberg and his wife of seven years, Jenny McCarthy. The touching video shows the dog going on adventures, snoozing and celebrating birthdays.

Wahlberg said his relationship with Lumpy began after his son Elijah convinced him to get a dog, 12 years ago. Donnie and Lumpy quickly became inseparable.

"Lumpy has been by my side — on set, on tour, on planes, trains, boats and automobiles," Wahlberg wrote. "Even on snowplows!"

"He's been a constant loving companion and a loyal friend to me and so many of you who got to know him. To some, Lumpy was a tv star, a rock star and a source of joy. For me — he was all of that and more. He was my best buddy. My family and I will miss him tremendously, as I know you all will too."

Fans were quick to offer condolences, even getting #RIPLumpy trending on Twitter for a time on Wednesday.

"As someone who always tries to find gratitude, even in the most heartbreaking of times, this situation is no different for me," Wahlberg wrote.

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"I don't mourn Lumpy today — instead, I celebrate his memory. I invite you to do the same. Thanks for the kindness that you all showed Lumpy through the years. He truly was — and will always be — the best!"