I know it is currently as designed, but can you please change the marriage selection back to left clicking?
If you go looking for someone to educate a child you left click, if you select someone in an elective government you left click, if you look at people voting in a law change you left click. Please a little bit of standardisation here would be great. <3
Just to continue on from this.
If you use the rings to arrange a marriage, it opens the possible targets and these targets need to be right clicked to select.
If you arrange a marriage directly at the target, left clicking selects the target and your courtier.
The only time you need to right click to select a marriage target is when you use the rings on the character screen.