Chaps get older, adjusting ratios of an unconventional relationship (6,1,5)
I believe the answer is:
menage a trois
'an unconventional relationship' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'chaps get older adjusting ratios' is the wordplay.
'chaps' becomes 'men' (I've seen this before).
'get older' becomes 'age' (synonyms).
'adjusting' indicates anagramming the letters.
'ratios' anagrammed gives 'atrois'.
'men'+'age'+'atrois'='MENAGE A TROIS'
'of' is the link.
Can you help me to learn more?
(Other definitions for menage a trois that I've seen before include "Triangular relationship(s)" , "household of unusual size" , "triangular arrangement" , "living arrangements" , "third party involvement?" .)