Miley Cyrus' brother Braison is dating her boyfriend Patrick Schwarzenegger's sister Christina Schwarzenegger, sources confirm to Us Weekly -- get the crazy details! Credit: Saskia Bagchus/All Access/Sipa USA; Inset: Kevork Djansezian/Getty Images

What would Maria say?

It appears another Cyrus has wriggled their way into the Kennedy clan! Miley Cyrus' model brother Braison is now dating her boyfriend Patrick Schwarzenegger's sister Christina Schwarzenegger, sources reveal to Us Weekly.

"They are dating and have been since a little after Patrick and Miley got official," a source tells Us. "Both Patrick and Miley approve of the relationship. Miley loves her brother and thinks it's a great match."

Us broke news in November that Schwarzenegger, 21, snagged Cyrus, 22, after years of harboring a serious crush on her. The controversial "We Can't Stop" singer hit it off with his famous dad Arnold Schwarzenegger last month — and also has fans in Christina, 23, and sister Katherine, 25.

"[They] were both fans of Miley before Patrick started seeing her. Christina wanted to hang out with her and met her brother and thought he was hot," the source adds. "They exchanged info and started hanging out on their own. Patrick and Miley were encouraging of it." (The new couple even posted an Instagram pic from NYE together on Jan. 3.)

Found another ??????????????

Uma foto publicada por braison (@braisoncwukong) em Jan 2, 2015 at 10:11 PST

Cyrus may be ecstatic about her 20-year-old brother's new relationship, but his mother Maria Shriver may not be as supportive. Earlier this month, Us exclusively reported that Shriver — the daughter of politician Sargent Shriver and Eunice Kennedy Shriver — isn't a fan of Miley and Patrick's budding romance.

"There is friction" between the couple and Shriver, a source told Us. "Maria told Patrick the more she hears about Miley, the more she's concerned." The former Disney star, for her part, has been trying to win Shriver's approval. The insider adds: "She respects Maria and has been on her best behavior."

TMZ was first to report the news.