'Hot Ones' Host Sean Evans Dating Porn Star Melissa Stratton

The guy who hosts "Hot Ones" might come across as a total buttoned-up square -- but he's linked up with a porn star in his private life ... TMZ has learned.

Sean Evans was among many recognizable faces out and about in Vegas during Super Bowl weekend -- but many people noticed he was hanging out a ton with Melissa Stratton ... who's a bona fide adult film star, cam girl, and model. And yes, she does explicit content.

Melissa had been posting a ton of photos of her and Sean all weekend across various social platforms of hers -- and in a lot of them ... they look awfully cozy ... almost couple-y, in fact.

Her captions also suggested there may be some romance afoot -- even though there wasn't any straight-up PDA shown between them in any of the pics she posted. Still, MS certainly appeared to be trying to telegraph something ... that's how many are reading it anyway.

From the looks of it ... Melissa and Sean were tied at the hip Saturday and Sunday -- hitting up clubs together, shopping centers together ... and even the freaking game itself together.

Like we said ... no direct signs they're for sure an item -- but that's definitely the vibe here, and that's for a very good reason ... we're being told they are, in fact, seeing each other.

Sources with direct knowledge tell us Sean and Melissa first started talking over DMs back in November, and first met in person at the end of last year. Since then, we're told they've hung out in different cities, including L.A. and Chicago, and more recently ... Vegas.

Our sources say Melissa is from Kansas City and is a big Chiefs fan -- which is why Sean invited her to the game. No word on whether they're throwing around the BF/GF label yet ... but our sources say they're without a doubt dating right now. So there you have it!

The odd thing, of course, is that while Melissa may be "claiming" him on her socials -- SE himself didn't post diddly-squat of Melissa on his own pages. Now, he didn't really post any SB-related stuff ... and his entire IG page is pretty corporate with promotional material.

So, at face value -- it appears she's perhaps more inclined to go public than he is ... but in any case, it's definitely eye-opening, just 'cause Sean kinda has this clean-cut rep about him.