The 27-year-old singer and Cody have been dating for at least two months, and after Cody recently spent Thanksgiving with Miley's family, things appear to be progressing serenely.
A source close to the situation told E! News: "Cody came out to Nashville for Miley's birthday and stayed for Thanksgiving.
"Miley's family loves Cody and was happy to have him stay. They all celebrated the holiday together at Miley's family house.
"Everyone gets along very well and Miley's siblings have welcomed Cody in. Their relationship is fun and easy. He's one of the crew."
Recently, Cody's family also gave Miley their seal of approval, with Alli Simpson - Cody's sister - revealing how fond they are of the pop star.
She said: "We love her. Cody is very happy and it seems that Miley is, too.
"We're always jumping on FaceTime with them. They always just seem so happy and I always say, if Cody is happy, we're happy. That's how we've always felt about our partners in life.
"If they're treating us well and we're treating them well, the family love it."
Cody also admitted that she and her famous brother are comfortable talking about their personal lives because they understand curiosity from fans.
However, she said they will also try to find a balance and keep some matters private.
She said: "It's something you have to get used to, it just comes with it, we're doing this as a job, being in the entertainment industry.
"People want to know about it, all of us are happy to talk about it, but you also want to keep it somewhat private, that part of your life too, it's nice to live your best life with your partner and keep it private ... we all just try and find balance with it."