Please do not post the name of the alleged offender in the public forums: I have removed it from your initial post.
See Help --> Report Abuse for the tools Chess.com provides to manage such behaviour - this includes blocking them and, if you deem the offensive behaviour serious enough, to report them.
Please also note that your avatar is somewhat on the borderline, and if you choose something more family friendly, that would be great.
Cheers,
David, moderator
Can someone tell me how to block a persistent sex pest sending messages of a sexual nature please.