Cheating?

So I've seen a lot of posts about bi curiousity on this site, and a lot of people sharing information so they could chat via snapchat etc, and a lot of them have stated they have male partners. 
So my questions are; do your partners know about the exchanges with another person? And do other people consider this cheating, or just a natural part of bi curiousity? 
I am not judging anyone nor trying to cause an argument. I would like to just know other people's opinions on the subject.