I make more exceptions this time around because I trust my partner on a much higher level but in the past I was a lot more cautious. To be honest, something as small as flirting was enough to start a huge fight. Now, almost crossing the line would be exchanging nudes (from someone other than me of course) in our monogamous relationship WITHOUT my consent first. I don't mind flirting because I know it's all in good fun, but sending things that I don't know about first or right after is an issue. Hanging out with another woman WITHOUT my prior knowledge is unacceptable, unless of course you run into the person and it's not planned, but if you plan it I'd better know about those plans! No reason to hide it it's not like I'll say no! And then of course certain types of contact. A quick hug around the shoulders is ok but please don't kiss her cheek. Just no.

In my relationship, basically cheating is going against what boundaries we have set within our relationship. He and I are both pretty jealous, yet at the same time very lenient, so boundaries are strange with us.

I could try to give a complex list of what is and isn't cheating in our relationship, considering at one point we tried poly. I just define it as going against set and agreed upon boundaries in a relationship with another individual. I think it's all up for interpretation.

What would end my relationship? If he went behind my back for an extended period of time planning on being with another person.

Almost crossing the line? To me, allowing an ex of his to flirt with him continuously even though she knows he is married. That bothers me.

I don't so much have grounds for cheat, as grounds for leaving. it seems like cheating (not mutually agreed upon sex with others) is either an escape valve for the relationship, or a way to end them. if an escape valve is needed, it needs to be fixed or ended.

To me, cheating is no certain action - there's no line like "well, kissing is okay but not having sex".

Cheating is a breach of trust.

My definition of cheating: doing or saying something that you wouldn't do or say if your partner was by your side. Pretty simple. I've had issues with jealousy before but i think it had more to do with fears of abandonment from childhood & an inferiority complex.

I agree with the others that say it's a breech of trust. If I feel he has deceived me, or intentionally hid something from me, it's cheating, even if it's minor. If he feels bad and guilty doing it, there is most definitely a reason. I am not a jealous or controlling type of person, so for him to get to that point, chances are it's not something "minor"