“性学专家”是干嘛的？

Sexpert（性学专家）是个合成词，源于sex + expert。性学专家或性学大师还可以称为sex therapist。

A person who professes a knowledge of sexual matters; A sex expert, especially a therapist who treats persons complaining of sexual dysfunction; Someone who has studied, or knows much about sex. This is the kind of person you can go to for advice and tips.
一个拥有性事方面专业知识的人；一位性方面的专家，尤指能为那些有性功能障碍人士提供咨询的治疗专家；这些人深入研究过性学，有很多这方面的知识，你可以向他们寻求建议和提示。

For example:
The sexpert would call this situation homosexuality.
性学专家把这种情形称为同性恋。

That lady on the Sunday Night Sex Show is a sexpert.
参加《周日深夜秀》的那位女士是个性学专家。

（中国日报网英语点津 杜娟）