@Osamu09 Its quite tough to decided how big the gap should be, but in my opinion if its a noticeable gap within the work then the tag should be applied, like for example the older person is out of the age group of their partner which is like 2-3 yrs, then the older partner should be at least 4yrs older.
would it be easier if we had terms that distinguish the types of agegaps maybe? like "decade difference" for those who are 8-12 yrs apart in age?
I guess this is one of those suggestions that might never see the light of the day if things keep going at the same speed. Anyway there's a similar suggestion for "age difference" and so my question is still: how little can the gap be?