Hey, Englishguy. I’d like to try and respond to your post or at least try.
That is an issue I have with dating or rather with the word “date” (on account of its implications of kissing in the moonlight and such stuff, as well as becoming boyfriend and girlfriend if things don’t go the wrong way within a short time-span). Just going out and having a coffee or film or dinner or a walk in the park with several different men or women is not wrong. At that stage you get to know them and you get to make your choice. It’s not that you should limit yourself to the first reasonably attractive or apparently compatible person (or both) that shows up on your path. But yes, there are constraints. There is a reason I don’t use the word ‘date’ unless maybe as a shorthand when I’m not delving into the ethical side of things.
You do but that’s when you enter into some more decided, more advanced interactions. Not necessarily physically advanced, could also be emotionally close in a way that isn’t really the same as between a brother and sister. But at the point you’re still just talking to people, even though you have marriage as your ultimate goal in mind, you’re meeting people, choosing, selecting your material. You need this part.
On the other hand, I believe that when you move on to building a relationship or some form of “benefits” (that a “just friendship” would not confer), when you would swap Valentine’s cards and stroll the lover’s lane in the evening or hold hands and look into the stars or carve initials in the tree or whatever else loving doves do, with two or more different persons, then yeah, something’s wrong there.
You don’t necessarily break the other person’s heart but yes, I do believe that a simultaneous approach to checking people out (one that does not stop at conversations over coffee or otherwise, well, conversations) is not really a great expression of human dignity or respect.
When it evolves into having something like multiple

boyfriends or girlfriends until one chooses just one of them, then it’s basically building n-1 relationships that are from the very beginning meant to be temporary, to be disposed of at some point. I can’t fathom how people can think this is supposedly better than what they call “serial dating”. I believe “multiple dating” is worse than “serial dating”, at least when dating means some form of relationship.
If I were the father of a daughter, I wouldn’t exactly be thrilled to see her as the girlfriend of a guy who had some other girlfriend or girlfriends too. Obviously, a slip like the OP’s, where he wakes up and thinks, “I’m dating two girls, it seems. I need to do something about it,” is not the same thing.
For starters, it would be a good thing if the word “date” with all its implications disappeared from the asking out language if one intends to meet other people as well. I’d only use that word if the person were uniquely special to me in the romantic sense.
The above is connected with my belief that if a relationship needs to be formalised, categorised etc., it needs to be with one person. When it’s with more than one person, it should be discovering but not building or consuming. (And discovering does not include kissing. I’m not talking about mistakes here but about a general attitude.)