The popular porn star and OnlyFans creator's stuck on everyone's mind recently ... with a rep for Pornhub telling us yesterday was his most popular day on the platform ever.

He previously set personal highs in searches in March and then earlier this month ... but, Tuesday's number blew both those days out of the water. We're also told Girthmasterr's consistently growing in popularity ... swelling to higher totals.

Part of that may be due to a clip catching eyes all over social media featuring Girthmasterr talking with the social media team behind Getahead ... described as a Tinder-like app for prospective employers and applicants.

In the clip, Girthmasterr explains who he is and says he makes somewhere between $40k and $80k per month showing off his impressive package ... and, it's got many people on the internet in a tizzy -- including megastar musicians. His penis is apparently the width of a wine bottle, BTW ... so that's what we're talking about here.

Girthmasterr's most popular day on PH comes on the heels of Cardi B acknowledging him on X ... posting the monstrous Alaskan Bullworm from "SpongeBob SquarePants" -- pretty clear what she's referencing here when you look at the pic.

In response, Girthmasterr fired off a tweet asking Cardi to give him a chance ... though we don't think she's looking to get into the OnlyFans game!

BTW ... Girth admits he's in the top .1% of earners on OF ... so, before anyone goes stripping down expecting to make five figures, ya might want to rein in your expectations.

Plus, GM says he's working between 60-80 hours a week on his platform -- saying he does a couple shoots each week -- so, it's a lotta long hours to make that money ... even if we don't hear Girthmasterr complaining about it.