Sophie Rain Doubts Lil Tay's Claims of Off-the-Charts OnlyFans Cash

Lil Tay is making headlines for allegedly rolling in dough after being on OnlyFans for only two weeks ... but another star who's raked in millions on the adult site is calling BS.

Here's the deal ... Lil Tay claims she's made $15 million since she debuted on OF ... and she used the Benjamins to take a shot at dethroning Sophie Rain, who also made bank on the site pretty damn fast.

Sophie tells TMZ … she finds it very hard to believe Lil Tay has made the millions she claims in such a short amount of time … 'cause that kind of cash takes months to pile up -- and you need a damn good team to help market you!

Don't get it twisted ... Sophie tells us she's got nothing against Tay, and it could be LT is even telling the truth about her bread … but Tay seriously needs to STFU about her, 'cause Sophie's over the manufactured drama.

SR figured after she became a star, there would be haters coming at her -- witness Lil Tay and Annie Knight -- but Sophie tells us she couldn’t care less. It doesn’t get to her ... and she only addresses the trash talk when asked.

TMZ's recent documentary "The War Over OnlyFans" explored both sides of the 18+ porn site -- the glam platform making some people millionaires ... versus the toxic platform destroying lives.

Sophie tells us ... she's managed to navigate all the pitfalls of what makes the site dangerous for some by sticking to her boundaries ... no matter how much money she's offered to go a little further. And that means she's still a firm NO on nudity and sex acts.