Lopez, already a mom to 4-year-old twins Max and Emme, her kids with ex-husband Marc Anthony, retweeted her beau's announcement, with an added note about the pup's name. "So happy!" she wrote. "LilBabyBear. Could get confusing!"
"Bear" isn't just the couple's pet's name; it's also their pet name for each other. Both Lopez and Smart have used it in the past as a term of endearment on Twitter.
"BEAR!!!!!!!!!!!!!! Today is OURS!!" the "Dance Again" singer, 43, wrote on the micro-blogging site for her one-year anniversary with Smart in October. "Thank you for sharing your beautiful smile with me everyday!"
Her man responded in kind. "Happy 1 year anniversary to the most gorgeous, kind, sweet, funny, beautiful lil Bear in the world..." he said on Oct. 25.
Adopting a puppy together is a big step, but Lopez and her love seem stronger than ever these days. "[Casper's] fantastic; he's like my best friend," the former American Idol judge told Harper's Bazaar in a recent interview. "I can tell him everything, when I'm feeling down, when I'm feeling good. He gives moral support, endless love and support."