Good call about, initially, stretching tight thong (1-6)
I believe the answer is:
g-string
'thong' is the definition.
(I've seen this before)
'good call about initially stretching tight' is the wordplay.
'good' becomes 'g' (abbreviation).
'call' becomes 'ring' (telephone call).
'about' says to put letters next to each other.
'initially' says to take the initial letters.
The first letters of 'stretching tight' is 'st'.
'ring' after 'st' is 'string'.
'g'+'string'='G-STRING'
(Other definitions for g-string that I've seen before include "Skimpy loincloth" , "minimal coverage" , "Violin catgut - stripper's garment" , "Minimal wear" , "Air on a - -" .)