Mysterious

There is a guy that I work with that states that he is "in love" with me. We have never dated and in fact I am currently in a relationship with someone else. Anyway he and another coworker thought that it would "funny" (and I use the term loosely) if they used a key to let themselves into a bathroom that I was using. They didn't see anything, THANK GOD, but I am mortified. I have discussed it with them both but he just doesn't get it! He gave me an half a** apology (that I didn't buy). And he keeps asking if I am over it yet. I am ready to throw the friendship away. The question is, does anyone think that I am overreacting? If they had seen me half naked, I would have been humiliated. Anyway, let me know what you think. Thanks in advance.