My father relation with other women

Hello sir, My father is retired from govt.job & we (me,my mother,my father,my brother ) live happily before his retirement,but after his retirement we suddenly came to know that ,my father has an affair with other women & they have two girls too ,so we are shocked and that women & his girls are torching to my father for money & they also wanted share in my father property so in this matter what i do ???? apart before retirement my father was giving him monthly money.