Depends....If we'd known each other for a while, and only just got round to a "proper" date, then probably!
If it was a relative stranger, then probably not. But then, I don't think sex outside a meaningful relationship is that big a deal, just a bit of fun. It only becomes important when there are feelings involved.
So called promiscuity is only a bit sad when someone uses it to fill a void in their lives, or get people to like them. Apart from that, I've no problem with it. Safety first, of course.