Depends on the state. You can go to the site below, which has ages of consent, along with information on different ages for homosexual sex, in some cases.
You can click the link for each state for further explanations. In some states, the scenario you mention would be legal. In others it would not.
http://www.ageofconsent.com/ageofconsent.htm
Do you think the Supreme Court will allow those differences will be allowed to stand?