The official announcement comes more than a year after her rep denied reports that the pair were engaged. In the post, Brown tried to address the criticism about their relationship and pointed out that Gordon isn't technically her brother.
"I'm tired of hearing people say 'eww your [sic] engaged to your brother or if Whitney was still alive would we be together or would she approve of this,'" she wrote. "Let me clear up something, we aren't even real brother and sister nor is he my adoptive brother. My mom never adopted him. In fact, mommy was the one who even said that she knew that we were going to start dating. My mom knows me better than any of you. A lot of yall are saying that yall are only saying this all out of love. Which is bull because if that was so, all you would want is for me to be happy."
Houston, who died in February 2012, took Gordon in over a decade ago. Although there is no evidence that Houston ever legally adopted him, he has been living with Bobbi Kristina in Houston's house for years.