hard to say without context. A sex line - could be a telephone service where people speak sexually to the people ringing the telephone number. The companies make money, the customers give themselves sexual relief. Without context that's all I can guess it would be. Chatline Sexline Sex Hotline ????

是不是走性感路线呢？

To be in charge of a business that takes calls. These calls are from men who want to talk about things of a sexual nature with women. They often pay per minute. Are you glad you asked?

Amanda, ignore Kalam. I don't think anybody here believes that just because you want to want to know what a sex line is, it doesn't mean that you want to be part of one.

Hello Amanda, Happy everyday. Wish you best of the luck. Dear Amanda, I think you are finding dirty in a good place. A human wants some demand in hidden or secret. After all you are girl. I dislike your question as a man from woman. Am I hurt you, please forgive me. Thank you. - - Kalam