It could be an occasion of sin, for you and for the waxer.
The purpose for which you got it could also be sinful. There is no need for such a radical procedure unless one is going to wear something immodest. Neither hygiene nor bathing suit fashion requires it.
I would say it at least comes under the category of vanity, with an intention to be immodest.
If one has other reasons, and one is married, and one does not display oneself in public, then perhaps it is simple vanity.