Last month, they appeared to adopt a Siberian Husky puppy together. Turner had posted pics of the pup, writing, "Meet the newest addition to the krew @porkybasquiat." She tagged Joe, who also posted his own pic of the dog.
Years ago, Sophie and her family adopted Zunni, the Mahlek Northern Inuit dog who played Sansa's late dire wolf Lady on Game of Thrones.
Joe will be the second Jonas brother to tie the knot. His brother Kevin Jonas, 29, has been married to wife Danielle Jonas since 2009. They have two daughters.
"Congrats @joejonas and @sophiet so happy to welcome you into the family!" Kevin wrote on Instagram, alongside the couple's engagement announcement pic.
Younger brother Nick Jonas, 25, also posted the pic on his own page.
"Ahh! Congratulations to my brother...and sister in law to be on your engagement," he wrote. "I love you both so much."
Joe's ex Demi Lovato had nothing but love for her former flame and made sure fans knew she was happy for the former JoBro. The singer wrote an excited comment to Joe's ring pic, writing on his Instagram, "Huge congrats! So happy for the both of you!"