That’s just not true.
It’s VERY true. The summer of free love and all the dirty smutty sex that implied was 1967, 1967 also saw the musical Hair which an entire song about dirty smutty sex. Bowie didn’t start getting hits until 1968 and didn’t become a personality driving fashion until the 1970s. The math is quite clear, teens having wild crazy filthy kinky sex BEFORE they ever heard of David Bowie.