Kristen Stewart Gets Motorcycle For 21st Birthday

Oh, to be a fly on this wall! Kristen Stewart celebrated her big 2-1 with "Twilight" co-star and beau Robert Pattinson over the weekend. The duo, along with guests (like Taylor Lautner) all hung out at Rockwell's Bar & Grill in Squamish, British Columbia on Saturday night (the actual day of her birth, for those wondering).

"Rob led the crowd singing for her, and you could tell she was so embarrassed but in a cute way!" a source told Us Weekly. "Everyone was in a good mood, but it was a bittersweet night [as filming is almost complete]."

The party-goers dined on treats like oysters, and at around 10 p.m., the birthday gal was presented with a "simple chocolate cake." KStew and RPattz have always kept their relationship on the DL, but they seemed to be getting a bit of PDA on at the low-key bash.

"Rob and Kristen were together all night," the source said. "They held hands and he kissed her cheek a bunch of times."

So what did the actress get for her birthday? Rob and the gang all pitched in to buy her a motorcycle! "Rob was so excited for Kristen and they each took turns riding it," the source said. "Kristen learned to ride a dirt bike in 'New Moon' so they thought it would be appropriate. Rob was supervising as she sat on it to make sure she was OK. They looked like they were having a great time, and it will be something they can really enjoy!"

Sounds like a great way to celebrate Kristen's big day!

What would you have gotten Kristen for her birthday? Tell us in the comments and on Twitter!