I agree with a lot of what’s been said here. Mainly that different people have different ideas about everything, including the nature of any r@lationship you might have. So if you want exclusivity, you need to bring it up and have a discussion about it. And then be prepared to accept whatever the other person’s views are on the subject. Never make any assumption about what the other person is thinking or feeling.
I know for me, it really depends on the nature of things. How often have we seen each other, how far have things progressed, are we in contact constantly, say if we can’t actually see each other that often, things like that. And I also get a feeling about how the other person feels as well. As I’ve been single (by choice) for a number of years, I know and have said repeatedly, I’d have to be really comfortable with someone before even thinking about becoming exclusive, and four dates sure isn’t it.
That being said, I’ve known people who met, clicked immediately, moved in together within days, and are still together. So not to say it never happens, but I think what it really comes down to is communication of expectations between both people.
I’m seeing this now with a friend. She’s been doing online dating for a couple of months, not much longer than that. Had some read duds, and now has met someone she really likes and claims to have “clicked” with. But they’ve been on only two “dates” and the second one she went to his place and spent the night, so we all know what happened (she told me so I DO know). She however, is talking like he is “the one” and has suspended her dating profiles on both sites she’s on, and putting all her eggs into this one basket. Me? I’m much more cautious, and perhaps a bit cynical and not as “trusting” but after such a short time, even though I may have hit it off with someone really well, and been “scrabble attracted” to them, it doesn’t mean and I wouldn’t think we are exclusive, nor that I need to actually act on the “scrabble attraction” part. just because you want something doesn't always mean its a good idea to act upon that want.