Are you talking about changes to words in your lifetime or throughout humanity? Considering how many words throughout history in the last few hundred years that have changed I would love to hear you speak.
Taking the above into account I assume you do not mean gay marriage (as the original meaning of gay has nothing to do with today's meaning) but same-sex marriage.
To be clear, because it might not be, I'm an not being passive aggressive here I am truly fascinated how you function in society with this stance and how anyone is able to comprehend what you are saying.