Brandi Glanville and Alexis Texas Have Mutual Friends in Porn Industry

Brandi Glanville's a 'Real Housewives' star with real friends in the porn industry ... which is how she linked up with Alexis Texas for their steamy photo shoot.

The reality star and actress tells TMZ ... Alexis was in town for business and asked Brandi to hop on her podcast "Private Talk with Alexis Texas."

The two hit it off ... and, they even realized they know the same people in the adult film world. Brandi's pretty non-judgmental about that kinda thing -- the parents of her son's best friend are actually in the industry too.

Glanville says she and Texas had such a fun time chopping it up, that they headed to the roof to get some sun ... and, they took a few sultry snaps, too.

We shared the pics with you ... Brandi and Alexis hanging around the pool, tiny bikini bottoms on revealing both of their impressive backsides.

They even took a pic where Alexis bent over at the waist and balanced a glass of wine on her booty ... a pro move only the likes of Alexis and Kim Kardashian on a magazine cover can handle.

Brandi's ensemble certainly took the focus off her face ... which has been through the ringer because of a mystery illness that Dr. Terry Dubrow swears isn't a parasite.