Christina Aguilera's boyfriend is "happy with her body." The 31-year-old actress is known for her fluctuating weight, but Matthew Rutler - whom she met on the set of Burlesque in 2010 - thinks she looks great, whatever her shape.

"Matt is happy with the way she looks, however it is. Even when she was looking heavier, he would always say, 'She looks gorgeous to me,'" a source said.

The couple got together shortly after Christina ended her five-year marriage to Jordan Bratman, and a friend claims no one expected their year-long relationship to become so serious. "We thought it was going to be a quick, seat-of-your-pants romance, [but] it's turned into something special," the insider said.

A driving force behind their success is believed to be Matthew's bond with Christina and Jordan's four-year-old son Max. "He recently surprised them by taking them to Cirque du Soleil's Iris show. They had a blast," the source said.

Christina debuted her new slim-line figure last week on The Voice, along with with a toned-down style makeover. However, she insists she no longer cares what anyone has to say about her looks. "I've been through my highs, I've been through my lows; I've been through the gamut of all things in this business. Being too thin. Being bigger ... It's noise I block out automatically. I love my body. My boyfriend loves my body. My son is healthy and happy, so that's all that matters to me," she said.