By dating multiple women at any one time your focus is split and not all on one person, it takes women usually a little while to be able to really start liking and feeling something for somebody so women assume the guys are the same. Girls don’t really tend to assume that men can look at a woman and end up feeling it right there and then, they will say things like ‘but we don’t even know each other’ ‘you don’t even know me’ ‘you don’t even know who I am, we’ve just met’. When you were dating any one person your focus and thoughts all tend to be on this one person so you end up going after her faster than she wants. By dating multiple women at any one time you can get to a point where it is actually not quite enough attention for her so she then starts picking up the slack by chasing you more and wanting to see you more. This is a great position to be in for the desire to build rather than too much too soon. That way the pacing is better.
Now jealousy seems to guys that don’t get it like a thing you want to avoid as if a women finds out you’re dating other women (without lying and saying you’re not) they think will blow their chances but actually it’s a great tool. Women want what other women have, if you have options as a desirable man then you become more attractive to women. It is a deeper subject as it communicates to a woman many subconscious things like, if you are with another more attractive women then you have options, you could pick better than her if you like, if she likes you then that means that you are desirable to women and safe to spend time with as the other women is spending time with you as we are bigger and stronger so could cause her harm possibly. As a women she would much rather pick someone who she can see women want rather than a single guy without women around him. The list goes on. It is now competition to get you for herself. Think of how many movies has a guy the girl could have but chooses not to, then the hot girl comes along and gets this guy and all of a sudden she desperately wants him and usually goes a bit crazy to steal him from this girl. It works…sometimes a little too well.