An anonymous female reader submitted a letter to Matzav.com that discusses her recent experiences with being led on by her dates, who gave off the impression that they were having a good time and wanted to continue going out, but then proceeded to give her "the talk" then dumped her, or just dropped her via the shadchan.
I am very much against the idea of giving false impressions of continued interest, building up a person's hopes and then dropping a bomb on them that shatters their expectations. It's not nice, it hurts, and people who do that need to develop a greater sense of being considerate of the feelings of others.
However, I also wrote about making sure the girl always has a good time, which created some discussion in the comments with points similar to this girl's letter on Matzav. I think the author of the letter is correct that a guy has no right to play with a girl's emotions on any level, especially if he is falsely projecting a positive, "I see this going somewhere" aura.
If you're going to go on a date, regardless of which number the date is, both guy and girl must be open minded about the possibility about continuing, but realizing that there may not be a future either. Going on a date with a foregone negative conclusion in mind is just wrong. It's a waste of time and energy. It drags on the emotions and really serves no constructive purpose whatsoever.
One of the most tenuous things about shidduch dating is that until you've had The State of The Union Address, the ongoing relationship is very "touch-and-go" and could literally end after that evening's date. It's a part of the system that is both good and bad. Good, because it shows you're dating l'toeles with the goal of marriage in mind, and not just to have fun with someone of the opposite gender. Bad, because this can be a bit nerve-wracking, given that there is no real guarantee of a future in the relationship until you've had that serious talk about where "we" are going. At that point, instead of simply thinking about your own perspective and perhaps discussing your feelings with the shadchan or a dating mentor there is a real "couple" of sorts that has potential. That's when the barriers begin to really break down, and the concept of "us" is even tangible.
However, as I wrote in that post, even a positive outcome from that conversation doesn't mean that this is it. Nothing is certain until he gives her an engagement ring, and even then, as many people are unfortunately/painfully aware, engagements can be broken (I won't go further and mention how divorce is always a possibility, because no one ever wants to experience that - better a broken engagement than a get).
Life is filled with uncertainties of all sorts, but we should all make an effort to lesson the anxiety that is often part and parcel of the dating process. True, a lot is on the line when it comes to shidduchim, but that doesn't mean we have to be uptight about every aspect. Nor should we go to the other extreme and make believe that things are always so amazingly positive that we can give off a false impression to the other person. As Rambam is often quoted as saying, the shvil zahav, or golden mean is the objective means to properly conduct a successful shidduch campaign, causing as little hurt as possible (though no doubt any rejection causes pain) and G-d willing you too will come out at the end of the journey with a travel buddy for life.