The photo was taken during the family's trip to Hawaii last month for the Aloha Golf Classic, which was hosted by their charity, the Mahomies Foundation.
"Ever snuggled a 400lbs dolphin?😍," Brittany wrote on Instagram.
Several commenters criticized the post before the animal rights group People for the Ethical Treatment of Animals (PETA) posted a lengthy response.
"We know you love companion animals, but we hope to see you extend your compassion to marine life too 🙏💙," PETA wrote. "In the ocean, dolphins swim up to 60 miles each day, but when used for entertainment, they’re confined to small tanks or pools 💔 Many dolphins develop painful conditions, such as stomach ulcers, and some die prematurely from the stressful conditions of extreme captivity. Not to mention, many illnesses can be passed from dolphins to human visitors, including viral, fungal, and bacterial infections such as salmonella. These types of interactions are dangerous for them AND us."
Both Brittany and her brother-in-law, Jackson Mahomes, have faced public scrutiny for their social media antics amid Patrick's historic success during his NFL career, though some of the negativity toward Brittany seemed to have lessened during the Chiefs' last Super Bowl run earlier this year. Jackson Mahomes was arrested on three counts of aggravated sexual battery (class A felony) and one count of battery in relation to an incident at a Kansas City restaurant in February.
Patrick Mahomes capped off a historic season with a gutsy performance in Super Bowl LVII, winning the Super Bowl MVP award for the second time in his career in February. The quarterback threw for 182 yards and three touchdowns on 21 of 27 passing, while also recording 44 yards on six rushing attempts, despite appearing to re-injure his late in the second quarter.
Mahomes scrambled for 26 yards on the Chiefs' final possession to setup deep in Eagles' territory with the game tied 35-35 just before the two-minute warning. A crucial holding call three plays later led to Kansas City running out the clock before Harrison Butker's game-winning 27-yard field goal with eight seconds remaining.
Mahomes' historic Super Bowl performance came just three days after he won his second Associated Press NFL MVP award, having led all NFL quarterbacks with 5,250 passing yards and 41 touchdown passes during the regular season. The 27-year-old had previously won the AP NFL MVP award during his second NFL season and his first as a starter in 2018.
The Chiefs have now won three Super Bowls in franchise history, which included winning Super Bowl LIV in February 2020.