Well,  the second guy's name is Yukito and CLAMP 
never did explain their relationship in detail,  
but from what IS explained is that Yukito and 
Touya are really good friends. There are sly 
hints at more though. I highly recommend seeing 
the subbed versions since the dubbed versions are 
not at all true to the whole theme of the show. 
Anyway, they still have the cutest butts 
though..he he

Diana ^_^