The specific spelling you mentioned—characterized by repeated letters—serves several purposes in modern digital English:
Just as someone might type "sooooo" instead of "so," the extra letters suggest a heightened level of attraction or enthusiasm [5].
Best for understanding the social context and intent behind non-standard spellings and slang [5].
While "sexxxxyyyy" itself is not a standard entry in the , the root word "sexy" is formally defined as: Adjective: Sexually attractive or exciting [2].