My best friend is getting married at 18 also.  Well we're not really best friends anymore, we used to be, but all he used to do was hang out with this girl, and then he moved to Cali.  I mean hes still my bro, but this girl has changed him a lot, and if hes happy, so be it, I'll support a wedding at 18 if he thinks the marriage will really last forever.  Although he always wanted to live in Cali, and now his fiancee is making him move back to michigan.  Lame, unless he really wants to.