My wife knows about it and she is aware why she keep on getting big watches as present. (45mm Michael Kors last time.) I can even comment to bar or somewhere to her that "Look, that woman has nice watch." or her hairdresser wears really nice and big watch. (I saw it when I took my daughter there.) and I always make jokes when missus is going to there: "Remember to check for me if Katy is wearing that her watch!"
I also sometimes ask her on mornings if I can put her watch to her wrist.
She is getting used to it, but that story is how it should be. My point is; whatever is the result, you should tell it to your girlfriend/boyfriend/wife to whom you have sex with. Not tending to make it biggest thing in world. (Even if it when talking about sex.) Just:
"Hey. Can you wear/put back/keep your watch. Its kind of sexy thing to wear when we have sex." (This is actual line how I told.)
"I bought you new watch. You know I like when you wear it. It looks sexy."
"Can you wear this sometimes. I know its your type, but at least every now and then."
Believe me. Its much easier to breath afterwards.