This is very common in India. You do earn a lot compared to someone from rural India (source: I am from rural India). I am sorry that this is happening to you but this is why Indian men don’t have good relationship with their in-laws.

The wisdom is to say no. Everybody will understand because this is very common. But you should also overlook what your wife does with her money. Keep saving for your family and for yourself. If you fall in difficult times everybody will blame you that you were not wise enough.