Find out later in more detail from LN that Geoffrey isn't interested in being king, and REALLY cares about his brothers in an obsessive yet platonic way.  Has a picture of them behind curtains that he looks at every now and then with a glint in his eyes.  Also works behind the scenes to get the scummier nobles to "support" his rise to the throne so can keep an eye on them, collect evidence to crush them when necessary, and foul any plans of theirs to ruin or assassinate his brothers.  Like Alan and Mary he and Suzanne are pretending to be fiances so don't have to deal with parents or annoying letters.  Suzanne is Raphael's boss and became interested in him due to him wanting to protect Katarina.  For some reason Suzanne became interested in Katarina after seeing her at the mentioned birthday party, likely for similar reasons as Jerold, and looks at Katarina with the glint in the eyes as Geoffrey when he looks at the painting of his brothers.  Essentially very obsessed and protective, but not in a yandere way, at least not yet.