My wife can't stand to touch or be touched on her (or by) feet because of "cooties". I don't think the same way. Is she being unreasonable asking me not to touch her feet? Perhaps, but I'm willing to accommodate. It's all part of being in a relationship.
It would be unreasonable, however, for her to require you not to touch or be touched by other people's feet because of her fear of something imagined.