When someone keeps bragging and teasing and never carries through, what does that tell you? Why do they keep following you? Why do you laugh it off? You say you don't mindif they get married but they never do--Are you enjoying the little game of cat and mouse? I don't know how many othes have played this game, but it doesn't really matter, does it?
Why don't you decide how you feel about this stalker and challenge the stalker openly to see what they honestly have to say? They don't see to be able to get along without you? You may be enjoying having a stalker follow so you laugh it off. You are so sure there will be no wedding; how can you be so sure? Do you know their heart?
If this person is just a bragger, let them brag. Keep laughing. But it amazes me that you seem so sure that they never will take the plunge.