Twice. Definitely twice.
Bi = Twice
Semi = Every OtherSource: It’s the terminology banks use when discussing paychecks. If you get paid on the same days every month (like the 1st and the 15th) then you get paid bimonthly. If you get paid every two weeks regardless of the date, (like every other Friday) then you get paid semiweekly.
I get paid biweekly, which means the same as semiweekly here
Interesting, I've come to understand those prefixes to have the opposite meaning. I looked into it, and apparently the actual usage of bi vs semi is not super consistent, and has been historically ambiguous and especially difficult because of how confidently people tend to believe others share their understanding on the words.
Take the term biannual, for instance:
https://www.merriam-webster.com/dictionary/biannual
You'll notice a lot of the words you listed include both "twice per" and "once every other" in their dictionary definitions. Of course, dictionaries are descriptive and not prescriptive indicators of language, and I think it's fine to argue one's case to keep the terminology consistent at least within the bounds of a conversation.
I guess the takeaway is that it's good to have a context under which the terms are consistent, like with banking, but also important to understand that there are other contexts with definitions that differ, and that those different contexts aren't incorrect.
Nobody tell banks about fortnights
Both work with the following caveat:
the "twice" is "once with similar gender, once with different gender"
the "every other" is "every member of similar gender and then again with other gender"
Every other sexual would be semi-sexual
Twice. But, 2x0.
You can use fortsexually for every other sexual. That way bisexual can be reserved for twice sexual.
every other totally
Me, A. My partner, B, tentatively.
