Ashley Tisdale and Zac Efron looked to be getting pretty close over 4th of July weekend when the High School Musical co-stars were spotted playing around together at a Malibu beach house while celebrating Ashley's 26th birthday along with some other friends.

The two spent time fooling around together at the party, with Zac carrying Ashley around on his shoulders; and they also played on the beach earlier in the day.  Zac was spotted giving piggyback rides to Ashley along the waterline.

And you know who wasn't there? Ashley's close friend and Zac's ex-girlfriend Vanessa Hudgens.

Could something be going on between the two?

Not so - Ashley's been dating director Scott Speer, who filmed two of her music videos - since 2009; and she and Zac are nothing more than really close friends.

After the party she Tweeted, "So happy zacary made it to my party!!! He's my brother/best friend!!!"

We'll take her word on this one as Ashley recently vacationed in Mexico with Vanessa and gushed about what a great friend she is.