Robert Pattinson & Zac Efron 'Bromance' - Hottie Accepts ALS Ice Bucket Challenge With Ashley Tisdale, Kristen Stewart's Ex No Twitter/Instagram! [WATCH]

Remember back a few weeks ago, when Robert Pattinson was spotted hanging out with fellow Hollywood heartthrob Zac Efron at a Los Angeles bowling alley?

Well, ladies, it looks like the sexy bromance is just getting started!

The 26-year-old cutie reunited with "High School Musical" starlet Ashley Tisdale in order to complete the viral ALS Ice Bucket Challenge. The chilling (yet adorable) video was posted on Instagram on Monday (August 19):

zacefron: "#ZacEfron takes on the #IceBucketChallenge with @ashleytisdale, donates to the ALSA.org and nominates #MatthewMcConaughey, #RobPattinson and #ErictheActor! #StrikeOutALS."

Funny enough, Efron nominated the "Twilight" hottie to support the cause by also dousing himself with freezing H2O within 24 hours. He even calls him by the chummy nickname, Rob. How cute!

Just one problem, the 28-year-old British actor isn't on social media. No official Twitter, Instagram, Facebook - nothing!

If Pattinson does accept the challenge, will fans ever be able to even see it? Hopefully the two pals will come up with something witty and entertaining!