Adultery is conceived in the heart when you give yourself over to the lust of wanting to do it. God looks at the heart. It is also talking about another mans wife, because it is impossible to commit adultery with an unbetrothed or unmarried woman. The definition of adultery is to deal with another mans wife.
But I tell you that anyone who looks at a woman lustfully
has already committed adultery with her in his heart.
The word Jesus used is not wife as you erroneously repeatedly claim.
It is γυναῖκα which is woman, not wife. Now it can mean wife, also,
because wives are women, but by no means does it refer to wives exclusively.
It refers to all women. To say otherwise as you insist on doing is ignorance.