Not necessarily sexy, but its a fun accent way to say that someone's cute in a non-freaky way
the "sch" takes off like 5 creep points
so..
1. to make a girl with a sense of humor laugh, you can tell a girl she is schmexi as opposed to saying she is very pretty
2. For girls saying it to a guy, its a way to be funny and flirty but not all over him,
1. Grrrrrrrrrrrrrrrrrl, you 'tis muy schmexi, you workinn that updoo grrrrrrl
Someone who seems to have total disregard for others' feelings-- also someone unbelievably cheap. This type of person will go to a mcdonald's and order a regular hamburger, drive home, and put his own piece of cheese on it just to save the 15 cents it would have cost to buy a cheeseburger.
dude: hey man, I called fives on that seat, get up!
schmeitz: it's cool man, there are other seats. pick one of those.
dude (to someone else): God, that guy is such a schmeitz.