Where did you purchase the outfit?
You should use your words to communicate not your clothes. Dressing sexy isn't nessesarily about wanting to have sex. And your perception of sexy is different from someone else's.
If I'm in a relationship with someone, he already knows, and if I'm not in a relationship, I will let him know - very clearly - in other ways. Just because a girl is wearing something sexy, it doesn't mean she wants sex with you. People who think that are usually rapists.