People in an exclusive SR: What is considered “cheating” for you?

Everyone’s definition of what “cheating” is probably different. For example, if a young 20-something SB wants to start talking to a guy in a vanilla context, is that cheating in your SR? How are SB’s supposed to form a vanilla relationship eventually?

What about txts with others? Sexting? Seeking profile?

Curious what everyone’s thoughts are considering a SR isn’t exactly a vanilla relationship.