@Mojo Nobles are still humans. They can love their children just like anyone else. It would all depend on their personalities and how decent or horrible their lives otherwise were. In the first place, in the past, it wasn't just the nobles for whom marriage was a trade. It was that for everyone. The stakes might have been much smaller for poorer commoners, but for rich merchants it woud have been an equally big deal to make sure the marriage is a good deal and the family wealth doesn't escape into unwanted pockets. In fact merchants sometimes managed to marry into nobility if they found a suitably destitute noble. However, even commoner parents would have wanted to make sure their son or daughter gets a good spouse and would have rejected any love at first sight silliness, unless, of course, it looked very promising. In any case, a proactive fiance wannabe would need to approach the girl's parents, unless the girl was an orphan, in which case there might still be a guardian. Otherwise it was just the parents talking with each other and negotiating.