Play video content Exclusive TMZ.com

Gia Gunn's calling BS on Trisha Paytas -- not just for announcing she's transgender ... but for her ensuing apology she believes was just an attempt to save face.

The "RuPaul's Drag Race" star tells TMZ she doesn't believe for a second that Paytas is transgender, and says Trisha telling us she's not transitioning is obvious ... because she's not legit.

Play video content 10/9/19 TMZ.com

Gia says it's clear Trisha's behavior is that of a YouTuber using clickbait to gain followers, NOT a transgender person. She concedes Paytas may have some conflicted feelings -- including penis envy -- but doesn't buy her identifying as a man.

Gunn goes on to call Trisha a "privileged, white, cis woman" trying to take advantage of a label ... one that should not be taken lightly or exploited.

As we told you ... Paytas apologized for offending people in a lengthy, tear-filled video, but Gia's not buying that either. She thinks it's an insincere move to avoid being canceled ... and losing money.