Kristen Stewart posed with a guest at actor Max Thieriot’s wedding.

Kristen Stewart is keeping a stiff upper lip, and occasionally even smiling in the wake of her breakup with Robert Pattinson. She was spotted over the weekend at the wedding of fellow actor Max Thieriot and Lexi Murphy, partying hard.

Reports from people who were there say Kristen was in good spirits and sociable, surprising fans with her “extra friendly” behavior and her free-spirited dancing.

Thieriot co-starred with Kristen in the 2004 movie “Catch That Kid.”

Kristen played the lead as Madeline Rose “Maddy” Phillips, a 12-year old girl who loves to climb things, like mountains. Billed as an adventure-comedy, it also starred Jennifer Beals.

They apparently have kept up a friendship since then, and Kristen flew to Arizona for the wedding. She traveled alone and attended the wedding solo, but didn’t let that stop her from partying.

Kristen was generous with her time, posing for photos that made their way to Twitter and Instagram. She looked terminally hip in a sleeveless black dress and black-rimmed sunglasses.

One fan was pretty envious of mom and date who partied with the “Twilight” star, while she was stuck at home. “My dad & step mom partying with Kristen Stewart at Max Thieriot’s wedding. And he left me home. Alone,” she wrote.

“OMGEEEE DEAR KRISTEN, thank you so much for last night I had so much fun with you. from dancing to teaching us dance moves with John :’) talking to you was amazing and you are the sweetest person,” wrote another fan identified by the handle mrs_kelsey_bieber.

“I am still just so shocked that you hung out with us, you are beautiful, sweet, skinny like crazy, and a very good role model and I look up to you 100% of the time,” she added.

I am so sorry if you saw us staring at you it’s just we are huge fans and you are amazingly beautiful in every way. tell John I said hi. I miss you hopefully I see you soon. love you.”

mrs_kelsey_bieber apparently is Theiriot’s sister; she said in another tweet that she met Kristen for the first time at “my brothers wedding.”

Pattison apparently remained back in Los Angeles. But he’ll be shipping out next month to begin shooting his new film “Maps to the Stars,” with “Cosmopolis” director David Cronenberg.

He’ll be in Toronto for filming starting July 8 and will be through through most of August. No word on whether Kristen will drop in for a visit. But follow TheImproper on Twitter. We’ll be the first with reports on Kristen you can trust.