I don't remember exactly what it was that got me thinking about this, but I'm a little curious about something.  FYI: as with anything else, I'm open to input, but with this one, my whole purpose is to ask the question, so I'm outright asking for input.

  Anyway, this is about the idea of not wanting your partner, or vice versa, to have sex with anyone else when one or both of you have already had consenting sex with someone else before becoming exclusive.

  First, let's exclude concerns about diseases and pregnancy.  This is about the exclusiveness.  This is about the psychological side of cheating.

  You don't need to be emotionally involved with someone in order to have sex with them.  You can even hate them and still have mutually consenting sex.  So, let's include another condition: there is no concern about either person becoming emotionally involved with the third party.  I guess this is for people not already in open relationships.

  Since you've already had sex with more than one person, obviously sex is not exceptionally sacred to you, in regards to exclusivity.  -(please excuse my lousy wording of the previous sentence)-  I mean, if sex was that important, in that regard, then you would have made a hell of a lot more certain (or should that be just plain certain?) the first person you had it with was the person you'd be staying with before having sex with them.

  So, if it's a given that there will be no diseases, pregnancies, a partner leaving, or any other outside complications, like fourth party conflicts, then why would you not be okay with your partner having sex with someone else?

  The only answers I can think of right now is an irrational sense of insecurity and/or a hypocritical sense of sacredness.  Please give me your thoughts, folks.

  For anyone who may be trying to read into all this, resulting in a conclusion that I'm trying to promote or justify conditional cheating, I'm not.  The act of sex and partnership, together, are extremely sacred to me.  Many people on this planet probably could not even comprehend my brand of exclusivity, and probably would not care to try to comprehend it.