Question regarding Masturbation?

I know very well that Masturbation is not allowed in islam. But I have some question regarding it like 1) is it ok if none of my hands are involved 2) is it allowed to Masturbate after marriage 3) can wife do it for the husband (Masturbation thing) with her hand and so vice versa can husband do it for the... show more I know very well that Masturbation is not allowed in islam.
But I have some question regarding it
like
1) is it ok if none of my hands are involved
2) is it allowed to Masturbate after marriage
3) can wife do it for the husband (Masturbation thing) with her hand and so vice versa can husband do it for the wife
4) is ******* allowed (I believe certainly not)

*ps
** If one have two wife can they have threesome together
** can one wife look at other wife naked


please help me with my doubts
and please answer in the light of hadith

advanced thank-you
3 answers 3