A little over a week ago, we reported on a story from the print edition of US Weekly that claimed that Kate Hudson was dating a British rocker named Matthew Bellamy who sings for the band Muse. The news was that Kate and Matthew met at Coachella in April, but that everything was so new that “it could be a fling.” It looks like things are getting a little more serious for Kate, 31, and Matthew, 32. People Magazine reports that two were spotted out in Paris on Sunday, where Matthew’s band had performed the night before.

The actress hopped a plane to Paris over the weekend and attended the second of two sold-out shows for the British rock band Muse Saturday, standing in an audio tent amid a crowd of 80,000 at the Stade de France.

The next day, she was spotted around town with the band’s frontman, Matthew Bellamy, who is a singer, guitarist and songwriter.

The pair were seen strolling through the Place Vendome, a square in the center of Paris. “They seemed very much a couple,” a witness tells PEOPLE. “Just walking together, enjoying the sunshine.” Later that afternoon, Hudson and Bellamy opted for a late lunch on the Left Bank at the celebrated Brasserie Lipp, leaving through a rear exit of the eatery when photographers turned up outside.

[From People]

That sounds so romantic and I hope this turns into something long term for Kate. She’s certainly had enough high profile relationships, though, and she would do well to try to keep this one under wraps. Musicians aren’t known as the most faithful, but neither are sports stars and world class athletes. A couple of you noted in the comments on our earlier story that Bellamy has a live in girlfriend. From what I could find, he used to be engaged to an Italian woman named Gaia Polloni, but they supposedly broke up in December of last year.

There’s still speculation that Kate could be pregnant considering that she’s sporting larger boobs and has filled out a little. I just think she gained a little weight and that she gains in her stomach, but it’s hard to tell. I thought that she was pregnant a couple of years ago when she gained a small amount of weight. If she’s not pregnant, then she had a small boob job earlier this year. In Touch had a whole article this week about the trend for smaller boob jobs in Hollywood. They cited Kate, Megan Fox and Nicole Kidman’s breast augmentation as examples of mini implants. They wrote that “Celebs who want to be taken more seriously [than reality show celebrities with huge chests]… want the focus to be on their work, not whether they’ve been artificially enhanced.” An “image consultant” told In Touch that “With smaller implants, they can still achieve a more feminine look and feel more confident without the stigma. It’s a win-win for them.” There’s always the risk that the tabloids will think you’re pregnant, though.

Here are some pictures of Kate out with her son on 6/8/10. There could be something to those pregnancy rumors, but I’m not going to pass judgment yet. Bellamy is shown performing in Paris on 6/13/10. Credit: Fame Pictures