Nominflexible is a term for someone who usually identifies as nominsexual, but whose identity/attraction is flexible. Most of the time they are attracted only to people who are not masculine (regardless of their actual gender), but they experience occasional tendencies to be attracted to people who are masculine. One may primarily experience attraction to those who are not masculine, but have occasional exceptions to their identity.
The opposite of nominflexible is minflexible. The feminine counterpart is nofinflexible.