High School Musical
star Ashley Tisdale
is celebrating her 26th birthday this weekend ... and she got a little help from one of her co-star BFFs
. Zack Efron
- who you may recall famously dated fellow HSM
castmember Vanessa Hudgens
for, like, EVER before they broke up last year - came out for Ashely
's party and the couple looked like they were having a GREAT time! Now, I'm not saying there is anything romantical ...