Is this a taboo?

Miss P I'm in trouble please help me beg your readers to advice me. I'm 29 years old, unmarried sexy and have figure 8. The problem is my 55 year old mum remarried a very rich 70 year old Lagos business tycoon.I'm sure you read about him in the papers.
The moment he saw me, he fell inlove and has been spoiling me with gifts and cash.He says he wants to marry me and if I give him the go-ahead, he would dump my mum for me.To say the truth,I love him.He is everything all my younger boyfriends are not.
The thing is my mum at 55 and shouldn't be thinking of re-marrying.We lost my dad 5 years ago and should be mourning instead of marriage ..We fought because of it .She has noticed he has changed and is complaining to me and I'm tempted to tell her the truth
I almost told her until she said"If i catch any small girl with my man, I will kill her"".I know she is capable but I'm her daughter .
Miss Petite readers, please If I let him dump her for me will she kill me? Or should I ignore her and tell her.  Afterall she has lived her own life and maybe this man is my missing ribs
I'm waiting for your urgent response.Thanks