My DH is obsessed with Star wars and inparticular Darth Vader, he is always talking in a Darth Vader voice and is always playing the DV death march whenever he's on the pc. If was funny at first but its starting to get a bit annoying, he does it when we're out which I find embarrasing, he does it when he answers the phone if he's expecting it to be for him and has even stolen one of the kids batman capes and runs around in it pretending to be Darth Vader whilst playing with the kids. It came to a head yesterday when we invited his parents for dinner, when they got here he got his dad in a headlock (this part was normal, they always play-fight!) but during the struggle he started saying "your powers are weak old man" etc... My sister burst out laughing and her husband looked confused and shook his head smirking at my sister, they were blatently taking the piss. I felt embarrassed for him. I know he's only playing and its better than being misserable etc but he does embarrass me with me, my parents bought him a talking darth vader mug for christmas for a laugh but to me it seems that everyone just seems him as a geeky joke.
Would you just leave him to it or try and get him to stop? it really does grate after a bit.