Yes. A couple where one person wants everything "normal" in a regular relationship, plus a fetish addressed (and, philosophically, having your needs met is part of a regular relationship) while the other half of the couple wants the "everything" but doesn't want the fetish part, even though they both connect on everything else. So someone would have to compromise, and since fetishes really don't go away on their own, at least one person will probably always have to deal with an emotionally fragile spot in the relationship. Either the fetish person going without, or having to go outside of the relationship to feel wholly normal; or the anti-fetish person giving in and indulging in something that individual is uncomfortable with, all the while the other partner is aware of that. Marriages have ended over this, and making it a simple "masterbation aid" argument ignores the complexities of humans, and the further complexities of their couplings.
As long as everyone's honest and up front about what they need and what they're doing to fulfill those needs, I'm not judging.
But if people aren't making things clear about those before they get married, it's their own problem.