Jason Momoa and Chris Pratt had a surprisingly frank back-to-back on social media over Pratt’s use of a plastic bottle as a prop in a recent shot.

It all started when the Aquaman star, who is an environmental activist, chided his Avengers co-star in a comment under an Instagram shot of him posing with a plastic bottle. “Bro I love you,” Momoa wrote, before asking why he was using a water bottle. “No single use plastic. come on.”

Pratt immediately owned it. “Aquaman! You’re completely right. Dammit. I always carry my big gallon size reusable water jug with me too. I even had it that day!!!” Pratt started his reply. “If I remember correctly somebody threw that plastic bottle to me in the photo shoot cause I didn't know what to do with my hands.”

The Guardians of the Galaxy star continued: “Love you too buddy. My bad. I don't want your home of Atlantis covered in plastic,” Pratt wrote. “Hear that kids? Reduce. Reuse. Recycle.”

That seemed to soothe the Game of Thrones star, who had second thoughts about the harshness of his response. Then he shared a shot of Pratt, himself and his kids, writing:

“I’m sorry this was received so badly today I didn’t mean for that to happen. I’m just very passionate about this single use plastic epidemic. the plastic water bottles have to stop i hope u make a reusable water bottle for amazon so we all can purchase. You’re an inspiration to many I’m one of them.”