👆🏼Your opinion.. What is considered Cheating and what is not?

Cin
If your S.O watches porn is that cheating? What if he/ she goes to a strip club and watches naked ppl there? is cheating just when there is physical touch? Or when someone is in a relationship and looks at another and lusts after them is that cheating in their heart? what do you say...?? im curious to know ppls opinions?