Aaron Carter is no stranger to falling in love fast.

After an impromptu marriage proposal in September to Kari Ann Peniche, his girlfriend of just a few days (they called it off six days later), the House of Carters star has been swept off his feet again.

Carter, who turned 19 on Dec. 7, celebrated his birthday Friday night at Shag in Hollywood with his twin sister, Angel. And on his arm was 18-year-old Kaci Brown, a singer who opened for the Backstreet Boys during their 2005 summer tour.

“Now I’m in a great relationship. I’ve only known her for, like, seven days, but I have a connection with her that’s like nothing else I’ve ever experienced,” he said. “It’s really amazing.”

Brown, a good friend of Angel’s, and Carter began their romance in Miami last week while celebrating his birthday. Asked what Brown gave him for his big day, Carter replied: “She got me love.”

And now that he’s older and wiser, Carter says he’s learned a lesson or two about love. “There’s a lot of things I’m gonna change – me for one,” he said.

“Love shouldn’t be about jealousy or anything like that. It should be about commitment and being able to trust that person. If you can’t have that from the get-go, there’s a problem. When it comes to relationships, I think I’m pretty experienced – you’d be surprised.”

He’s even met the parents: Before the party at Shag, Brown’s family invited Carter over for dinner. “It was so funny – Aaron told them not to worry,” Brown said. “He’s just one of the sweetest most genuine people I’ve ever met. He’s so talented and it’s inspiring.”

What did Angel say about her friend dating her twin brother? “She encouraged it,” said Carter. “She wanted us to go to Vegas and get hitched!”