crush = u first time see her and like her, most likely due to
looks. Common in Primary up to JC level. Duration is shorter than
infatuation. can be as short as 1 day....
infatuation = u like to bio her always and is, most likely, again
due to looks. u will try all means to get a glimpse of her
etc...Duration is long and can be rather long.
Infatuation can lead to serious problems while crush won't. Do take
note.