Hayden Panettiere IMG_0008.jpgThe birthday girl earlier in the day

We spotted Mario Lopez making his way into Hayden Panettiere's birthday party at the LG House last night with a gift for Hayden's mom the birthday girl, although unfortunately he wouldn't let the contents of the bag he brought slip from his lips. Of course, he wasn't the only attendee - other visitors making their way up to the LG House in Malibu included Rumer Willis, Hayden's (much) younger brother, and a whole gaggle of her Heroes co-stars, including recent newcomer Kristen Bell. Oh, and keep an eye out for the slices of cake Hayden sent out to the paps waiting outside! How sweet - and we're not just talking about the cake!