Your best remedy is to start looking for another job. You may also want to contact the US Department of Labor' Wage and Hour Division concerning this company's approach to FMLA. Keep in mind that if you file a complaint and are the only one with this issue, the company will in all likelihood identify you as one who complained and retaliate. Even though such retaliation is unlawful, if the employer has another legitimate ground for its action outside of retaliation, you will have a difficult time maintaining an action against the employer.
This is meant as general legal information and is not to be construed as legal advice in an attorney client relationship.
This certainly sounds like impermissible interference under the FMLA. Question is what damages you are entitled to, as the FMLA does not provide for emotional distress, and it does not sound like you have lost wages. If you do not receive the promotion because of taking leave, then you likely can receive damages for that, which would be the difference between your current salary and the salary of the new position. I also wonder if there is impermissible gender stereotyping going on here - e.g., a belief that a woman can take leave, but a man is not supposed to. That would be a violation of the Civil Rights Act - Title VII, enforced by the EEOC. You can, but are not required to, report an FMLA violation to the Department of Labor. Often that agency will not take action. You are required to report a violation of the Civil Rights Act to the EEOC, usually with 180 days of the wrongdoing. Note that the EEOC does not have jurisdiction over the FMLA. Complicated, right! Though I am biased in this respect, I think it worth your time to contact a lawyer. Best of luck with what is a difficult situation.
Note that this is not legal advice and this does not establish an attorney client relationship. You should review your issue with an attorney for the best possible answer to your question.