Which had nothing to do with the point I brought up, but which I also have a problem with.
My original point was that it is not sufficient to merely avoid lying about being in a non-exclusive relationship. If one knowingly withholds the information that one is in a non-exclusive relationship from the multiple people one is dating evven though there is the possiblity, or even worsse, the likelihood, that any of them look at their relationship with you as exclusive, then there is a
huge problem. That is deception by omission. It is not technically lying, but is still an unacceptable form of deception, which is why I was pushing him to make sure to explicitly tell them that he views the relationship as non-exclusive. Now, I realize that by lying you might have been including this kind of deception, and if so thats all fine and dandy, we’re on the same page, it just seemed too easy for someone to come along and read that all they had to do is not lie and then it would be ok, and so go on to deceivve others through omission, all the while thinking their doing nothing wrong, because, well,
technically they’re not lying.
My new issue, now that you point out that you think exclusivity is only necessary for serious or engaged couples, is that the nature of the emotional attatchment between people that must develop before a couple becomes very serious or engaged is exclusive. Once that emotional attatchment begins to develop, and once the couple start to nourish that emotional attacthment, the relationship should be exclusive. Maybe our difference in opinion is coming from a different understanding of what counts as “seriously” dating. If it does we might actually be in agreement about the essence of what we’re saying and just be using different words to express it. Hopefully this is the case.

All I know is that I would be seriously hurt and feel as though I had been treated unfairly if I found out that a guy I had been dating and becoming emotionally close with was also dating other women at the same time. I would feel personally violated and as though he had broken my trust. I know I am not the only woman who would feel this way, and I would certainly expect this kind of exclusivity long before I would truly consider a relationship “serious”, but again, perhaps my definition of a serious relationship is different than yours.