Nathan Sykes of the Wanted is sending his friend Justin Bieber "a massive happy birthday!" As many already know, Bieber turns 18 today, March 1. PopCrush was able to catch up with Sykes before his show at LG Arena in England -- Sykes, along with his fellow Wanted members, opened for Bieber at a few concerts in the past -- and the 'Glad You Came' crooner had some important advice to share with Justin on this momentous day. 

"My main advice to him on his 18th birthday is to...," Sykes, also 18, said before trailing off. He then continued, "As much as we all know how much he loves America, and everybody knows how much we love America, on his 18th birthday, he can't be in America." But why, Nathan? His reasons are simple.

"[On your 18th birthday], it's traditional in the U.K. to drink as much as possible," Sykes said, before adding, "[while] obviously being sensible at the same time." Sykes also told Bieber to"just have a great night" and said that the 'Never Say Never' hitmaker "deserves it with the amount of hard work he's done."

Since the Biebs won't be able to party it up at the pub, with the drinking age in the U.S. being 21 years old, Sykes is also hoping that Bieber can hang with him and have a proper, drunken celebration with the rest of the Wanted crew the next time he's in the U.K. "But we have promised him, next time he's out in the U.K., we're gonna take him out and make sure he has the best night of his life."

Here's hoping that the guys from the Wanted don't drink Bieber under the table!