It is normal to have lovers in the king's game. People in the world often send messages to find girls or something. If your fiance likes playing king, don't stop him from playing. You can also download one, play with him, let him take you flying, and then persuade him to break up with that lover and form a lover with you.
Don't overdo it, it will hurt your feelings. Because I am also a king, don't worry, the problem is not serious, just communicate well and don't think too much.