Fetish behavior is perhaps the most confusing of all sexual behavior. How can someone get a sexual charge out of kissing a woman's calves or dressing up in a blue latex suit? No one is exactly sure of the answer, but this variation in sexual behavior is more common than you might think. Fetlife, a website just for devotees of BDSM (bondage and domination, sado-masochism) and fetishistic sex, has 2.5 million members.
Women sometimes contact me as a sex therapist to ask questions about whether a behavior is normal. Aside from responding with a Socratic, "What is normal to you?" my concern is whether or not the behavior poses any danger. For the most part, as long as a behavior isn't dangerous, and the activity is consensual (that is, both agree to participate) then it's okay to do.
Problems occur for a few reasons. One, and perhaps the most difficult to address, is that the fetishist did not disclose their fetish prior to making a commitment or marrying. The partner may discover evidence of the fetish and become upset or offended. Sometimes it isn't the fetish itself that is the issue, it is the fact that their partner is draining sexual energy away from the partnered relationship. Sometimes the behavior itself is so puzzling and far from the norm that the partner has difficulty understanding or accepting it.
The second problem is that if the partner consents to participating in fetish behavior, they may grow tired of it. It may not be their cup of tea, but they believe they will either come to enjoy the behavior or be able to accept or adapt to it over time. I'm certain this happens, but things can also go the other way. They may never come to enjoy the fetish, simply going along to make their partner happy.
Is it okay to engage in sexual behavior just to make a partner happy? I think everyone will have a different answer to that question. Some will say that if the relationship is otherwise a happy one, and it creates harmony to engage in such play, then it's fine. Others will say it is unfair, and may even try to get the partner with a fetish to drop it.
However, fetishes are very hard to treat. It may be difficult for people who do not have a fetish to understand, but for the person with a fetish, the drive to engage in such behavior is very rewarding. Even if someone tries to stop a fetish--often with a "purge" of objects and clothing associated with the fetish--the behavior will often return. That is why most sex therapists will recommend that the couple adapt to the needs of the partner with a fetish.
How that adaptation takes place is highly individual to the individual and the couple. A trained sex therapist--a licensed mental health professional who understands and treats sexual problems of all kinds--can be helpful in sorting things out. If your relationship is otherwise sound, it may in the long run be easier to adapt to the fetish behavior and to negotiate a new sexual contract that includes the needs of BOTH partners, than to give up on the relationship altogether.
Would be interested in your thoughts on the topic; your perspective may be much different.