What a shame!

[Plum]

Going by this, Swami(???) Nithyanandha has not done any mistake and he can be let free..

ofcourse, idhai thAnE appOvum sonnOm. If we stricrly apply that living together is an offence and punishable, consider this delicious possibility.

Man A marries Woman A.
Man A is powerful
Man A finds another woman desirable
Man A "marries" Woman B also in addition
Man A has children and grand children from both lines.
Man A becomes more powerful. Woman A and Woman B are happy with each other.
Indian constitution says only one wife is recognised - so the other one is what?
Per your argument, Man A is culpable. avarai arrest paNNalAmA?
(Imagine evLO man As in our society will be arrested - appuram nAdALa, cricket veLayAda, cinemala nadikka yaaru minjuvAnga)