This is one of the reasons Miss Manners is opposed to plus ones. If you're inviting someone to a dinner party, and you want to invite their significant other, find out their name and invite them. If you only want your friends, only invite your friends. If you don't want people you dislike at your party then you need to control the guest list, not pick and choose who you trust to bring a plus one you like.

Then, if you invite Ahmed's husband but not Lucy's live-in boyfriend, and Lucy is offended, she can choose not to come to your party. But you have the same rules for all your guests.