The Pussycat Dolls singer revealed at the MTV Video Music Awards that the couple are moving in together.
She has since commented that Hamilton is a "wonderful guy" and that their relationship, which began in November 2007, is progressing nicely.
"I definitely think he could be The One. We might be moving in together soon. Everything is going so well," she said.
The pair were recently reported to have had their luggage stolen in Spain.