Pretty common on this show for bed hopping and characters go from relationship to relationship but trying make a list of characters who only ever had 1 love on thire time in the show. So correct me on any of these
She kinda had thing for Kim but when she new and didn't understand social rules like why can't kiss more than one person.than was Jonah in the believer's who obviously manipulated her so not sure of you'd count him.
Noah? Know him Hayley on and off but can't remember him actually being with anyone else. I know Kit had crush on him but from memory never went anywhere so again leave this up for discussion.
Morag. I honestly can't remember her showing any interest in anyone other than Ross