Search for other ways to sexually arouse yourself when you have conflicting fantasies. Look for other things that turn you on. If that doesn’t work either, accept that you’re sexually incompatible. Return to the mainstream way of having sex, or open your relationship. Your partner might try out your fantasies, but don’t coerce them into it. If your fetish is one of the many desires, compromise with it. However,  if it’s compulsory for your arousal, but can’t open the relationship, consult a sex therapist.