I've had a couple of friends tell me that their online activity has created some problems in their relatonships. So, I'm not the only one asking these questions. But I do have some experience with this kind of thing, which gives me a unique perspective. I could go on and on about how it's disrespectful, hurtful, etc. to do anything outside your relationship that resembles flirting, or something that might spark another relationship.
I could. But I won't. Here's why.
No one is wrong to have a life. That includes relationships, of all kinds. The thing is, part of your "significant relationship" is listening to the other person and respecting what he has to say. If he comes to you with a concern and you ignore or dismiss him - now you're wrong. You may not agree that there is a problem - but you signed up to be part of the solution.
Maybe your outside relationships really are crossing a line. Maybe you are being disrespectful. Or maybe, there's something else going on that's causing a lot of unnecessary worry. So, you fix that, and the rest falls into place. You'll never know until to you talk and work it out.
Every person, and every relationship, is different. What works for some won't work for others. But here's one rule that I think makes sense for everyone: Don't do anything you feel like you need to hide.