Our current wiki for the tag josou_seme says
A crossdresser, trap, girly boy or otherwise effeminate male character sexually dominating a partner, regardless of that partner's sex.
Typically, however, "seme" is defined not as the dominant person, but as the penetrator. And we also have this alias: trap_penetrating.
It's true that he's usually both at once, but not always. That's what the power_bottom tag is for.
But because two contradictory definitions are used, the josou_seme tag can include situations where an effeminate guy is both a dominant uke and a submissive seme.
post #2779421 (submissive seme)
post #7307977 (dominant uke)
What should be done with such posts?
Related: forum #433465
