I love
Cassidy for a boy, I'm very fond of softer sounding boys names and tend to really like boys names that have gone unisex (ie.
Ashley,
Aubrey,
Ariel).
I've known several male
Cassidy's and only one female
Cassidy, I don't know how popular it actually is, but it isn't similar to either popular girl or boy names right now so I doubt a little male
Cassidy would have many female class mates to contend with.