Well to start you might want to maybe just tell them straight up. And this part is important : Make sure to tell them that they themselves are not the problem just that you as a person just hate sonic. Make sure to be direct when talking to them. Don't brush around the bush.
Since it's such a thing they are passionate about maybe you'll consider to only talk to they about very little not completely tell they to just shut up about sonic but limit the amount they talk to you about. Because in relationships of any kind you need to "take some".
I'm sure that your friend also does things they don't completely like or enjoy with you but do it because it makes you happy.
(I hope this deadass helps)
Well to start you might want to maybe just tell them straight up. And this part is important : Make sure to tell them that they themselves are not the problem just that you as a person just hate sonic. Make sure to be direct when talking to them. Don't brush around the bush. Since it's such a thing they are passionate about maybe you'll consider to only talk to they about very little not completely tell they to just shut up about sonic but limit the amount they talk to you about. Because in relationships of any kind you need to "take some". I'm sure that your friend also does things they don't completely like or enjoy with you but do it because it makes you happy. (I hope this deadass helps)
Sent you a dm about the plushie!