Is my own son fucking my Wife ?

I am 45 years old male divorcee and married to a divorcee lady aged 42, who is having two sons from her earlier marriage. We have no children of our own as she has done family planning operation before our marriage. The elder son of my wife's earlier marriage is 26 years old and unmarried staying alone in Mumbai. My wife visits him frequently and also my wife has maintained herself and keeps herself in sexy looks.

When ever my wife visits her son in Mumbai they both share the same bed. Also they are emotionally very close to each other. He is always trying to touch her e.g. keeping his hand on her shoulder etc. He also had sexual relation with a few girls/ married women which he shares freely with his mother i.e. my wife. He never talks to me as we are not having a good relation.

I strongly feel that my wife is providing her son with sexual relief while she is at his house at Mumbai. Please guide me whether this can happen in our country?

Eagerly waiting for your reply.