Classical:
If you love someone,
Set her free...
If she comes back, she's yours,
If she doesn't, she never was....

Pessimist:
If you love someone,
Set her free...
If she ever comes back, she's yours,
If she doesn't, as expected, she never was ...

Optimist:
If you love someone,
Set her free...
Don't worry, she will come back.

Suspicious:
(1) If you love someone,
Set her free...
If she ever comes back, ask her why.

(2) If you love someone,
Set her free... but get someone to follow her.

(3) If you love someone,
are you sure you love that someone?

Go-getter:
If you love someone,
Set her free...
If she comes back, she's yours,
If she doesn't, go get her!

Hunter:
If you love someone,
Set her free...
Don't even wait whether she comes back, go hunt her down!

Impatient:
If you love someone,
Set her free...
If she doesn't come back within some time, forget her.

Patient:
If you love someone,
Set her free...
If she doesn't come back, continue to wait until she comes back...

Playful:
If you love someone,
Set her free...
If she comes back, and if you love her still,
set her free again,
repeat