if you want him to reincarnate you should have reincarnated him into a baby or you should have made them have kidnap him after he was reincarnated, so that he could have taken their virginity. Now he is in body of the boy, I don't know how many times he must have fked those girls.
It would have been so much better if the MC had reincarnated before the 3 wives lost their virginity, it leaves a horrible taste in the mouth and in my opinion that was NTR.