Chiasmus

is a balance in which one part is syntactically balanced against another, but with the parts reversed.  Look for it here:  

"Sanctification of Love" by Frank V. Gardner

Love by S.M.(M).L.

                     Love is                       nothing you                 
                 expect. Love is  everything you don't want,              
but you like it.  Yeah, yeah love is patient,
 but often not. Love is funny and dirty
 and gorgeous.  Love is fantastic in 
the real sense and awesome in
 the real sense. Surprising and
constant.  Constantly
indescribable.
Constantly
 described.
Love 
​is

you reaching for my hand, and me taking yours.