Good point! Though it would be weird to find out that Fai could be like a hundred years old! He looks so young, hehehehe. 
I wouldn't be surprised if Fai was over a hundred years old.   ^_^
Mokona:  Whee!!   Happy birthday Fai!  
Sakura: It's Fai-san's birthday today?  
Kurogane:  What!?   He actually 
has a birthday!?
Syaoran:  Happy birthday Fai-san!  
Fai:  *smiles/grins*   Thank you!    Is this one of your Secret Techniques, Mokona?
Mokona:  Yes!  Number 35!   Birthday surprise attack!  *hearts hearts* 
Syaoran:  Um, Fai-san?  You never told us how old you were going to be.  
Fai:  Can you guess?  
Sakura: 26!  
Mokona: 24!
Kurogane: ........Bah!   You're young!  That's all I'm gonna say!  
Syaoran: Uh, 27? 
Fai:  None of the above!  I'm 264 years old now!   
Everyone: *stares* .............  O_o  
Everyone: Wh-------------at!?   
Fai: .......................................
 .........................Just kidding!  
Everyone:  *falls onto the floor*  
Kurogane:  What the!?   You don't look the age at all!  *veins*
FaI:  No, not really.   I'm actually 146 years old!  *grins* 
Everyone: *stares again* ....................
Fai: So, what did ya get me!?  Huh huh!?   You guys must have the best gifts ever!   *dances around*  
Everyone: *still staring*
(tg - thank you! It was a slow day today at work and I managed to read the first three volumes of xxxHolic as well (the joys of working in a bookstore, even if it is as of yet not very well stocked with manga))
You're welcome!   ^_^  Lucky, you work in a bookstore.  Even if your bookstore doesn't have a lot of manga, still....  It's paradise for many of us!    ^o^