to ruin the character of one mother at a time..
make her look like criminal..
make her utterly selfish and despicable
make her not see sense at all
they did that with Padmini during the wedding track..she asked Sultan to kidnap Madhu coz she thought she was saving her..she was totally made dumb
at that time Radhaji was doing all things right..how a good mother should be doing
Now Radhaji is acting all dumb..hiding the truth of a dead ex husband who was a cheat (if he indeed is) to save his repute and thinking she is protecting her son..does she not realise the son would shtter if he came to know the truth from.someone else
Now its Padmini's turn to act all good and giving sound advice to Madhu that she should tell RK the truth
So I guess its CVs motto: only one mother at a time can make sense