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What’s a gigolo seme

gigolo: a young man paid or financially supported by a woman, typically an older woman, to be her escort or lover.
just add uke in place of woman

Well, I don't think this is exactly what you're looking for, as he doesn't pimp the other one out, being a gigolo is just his job, but it's the only example I can recall:

http://www.mangago.me/read-manga/eunsuk_jung_gu/

The same author has an ongoing webtoon where the top runs a brothel, but it isn't as...well...mild and feelgood as Eunsuk & Jung-gu.

Thank you :)