Your suggestion @akashako doesn't hit the same as the 'mentally challenged' trope though. Your example exposes those problems: part 1 shows they have sufficient mental faculties, part 2 is describe drunk +25 which also overlaps with your description.

I would propose; "Sexually oblivious" "When a character is unaware that the sexual act they are performing are sexual." Worded specifically like that to not include non-direct acts done by someone that cause sexual acts to someone else. For example, when someone is messing with a remote that controls a sex toy being used by someone else, but they can't see that person. One example for sexually oblivious #110182 | Fresh cream Alice | 1,130

i also believe that a tag like this should exist, but we'll have to rethink the name and description more.

Similar tag suggestion create tag retarded rejected rejected.