Lies only leads to more lies and to more problems with no easy solution. The only way out of a lie is the truth. If you cannot be truthful then try to let the lie die out on its own. In time it may work out. I'm not sure who 'them' are and not knowing the details about the situation makes it hard to give any advice.
Is the reason why you're lying because he's Mexican & you're worried how they're going to perceive you & the backlash toasted him? Sometimes we lie out of fear. Fear not, be brave & tell them the truth. It is your life, love who you choose. If anyone has a problem about your choice, it's their problem not yours. Be happy.