Fans Notice Uncanny Resemblance Between Mark Wahlberg's Son and His Brother Donnie

Mark Wahlberg shared love for his son in honor of his milestone birthday—but some fans focused, instead, on how much the boy looks like a close family member.

In a new Instagram photo shared on Monday, Sept. 16, the longtime actor marked his teenage son Brendan 's golden year , posting a picture of the two together as they enjoyed a sporting event.

"Happy b day Benny!!!🥳❤️🥳 16 wow🙏❤️🙏," the proud dad captioned the celebratory upload.

There's no denying from the snap that the youngster is his dad's lookalike, however, some people likened him to his father's brother, his uncle, Donnie Wahlberg .

As several people dropped into the comment section noting things like, "he looks like you, only more handsome🎈🎂," "Benny just like his dad ❤️ love you Mark!😍" and "Twin," others brought the Blue Bloods actor into the conversation, instead.

"Bro...Looks Like Donny [sic]..." one noticed, as another echoed that sentiment, agreeing, "Looks like his Uncle Donny [sic]!! Happy Birthday!! "

Donnie is two years older than Mark, and he shares two kids of his own with his ex-wife, Kimberly Fey : Xavier and Elijah . Currently, the elder brother is married to Jenny McCarthy , who has a son, Evan , with her ex-husband, John Asher .

Meanwhile, many more people on social media simply kept it classic by sending resounding "Happy birthday Benny" messages and well wishes the growing teen's way.

In addition to Brendan, the 53-year-old The Union star also shares three more children with his wife, Rhea Durham : son Michael , 18, and daughters Ella Rae , 21, and Grace , 14.

Next: ‘Blue Bloods’ Fans Go Wild for Bridget Moynahan’s Photo With ‘Brother From Another Mother’ Donnie Wahlberg