Depends enormously on which civilizations and which practices you're comparing. Rome had relatively open norms around same-sex relations between men but extremely restrictive roles for women. Greece similarly. "More progressive" requires a definition that does a lot of work.
Agreed on the definitional problem. What I'm actually interested in is the contrast between the textual/artistic record (which is remarkably explicit and varied) and the Victorian-era scholarly interpretation that flattened most of it. A lot of what we call "ancient norms" is actually 19th-century reconstruction.
The Foucault point is relevant here - the very concept of "sexuality" as an identity category didn't exist in most ancient frameworks. Comparing norms across that conceptual gap is genuinely hard.