The Super Junior members celebrated Siwon's birthday on April 7 without the birthday boy in attendance!  It appears the members went for a big feast together for Siwon's 28th birthday but it appears Siwon couldn't attend due attending Jackie Chan's fan meeting in Beijing.

Ryeowook uploaded the above picture onto Twitter and wrote, "Rib eye day keke Siwon, happy birthday!!! ^^"  Siwon also celebrated his birthday on Twitter with a cute picture of a cartoon cake and, "well. happy birthday :^) lol [sp]."

Happy birthday to Siwon!  Make sure you also wish him a happy birthday when you can.

https://twitter.com/ryeong9/status/453037334535995392/photo/1