Sense Sonnet - Chiller

Marriage Means...?

For centuries, marriage has been
Men and women tying the knot.
Same sex marriage - oh God, a sin!
Polygamy still has a slot.
In recent years, the U.S.A.
Has done a poll turn about face,
Approving marriage, gay to gay.
The Supreme Court is on the case.
If gay marriage gets the green light,
It won't take long for lawyers to
Chase potential couplings and fight
In courts for equal rights - tiz true!

Could a father marry his son,
If marriage not man and woman?