Multiple stars of the 'Real Housewives' franchise are coming forward to defend Andy Cohen against Leah McSweeney's allegations -- and they're all leaning into the idea each cast member is personally responsible for her actions.

Luann de Lesseps, who costarred with Leah on 'RHONY,' talked to us Wednesday on "TMZ Live" about Leah's lawsuit against Cohen, Bravo, the production company Shed Media, and Warner Bros. ... claiming they took advantage of her alcohol abuse issues.

Leah claims she was encouraged by Cohen and others on and around the show to drink all in the name of creating better content for the program.

Luann, speaking from personal experience, didn't feel that was the case for her ... saying of course alcohol and parties are part of the 'Housewives' world, but no one ever forced her to take up a glass.

In fact, she says she doesn't think anyone can make a person drink, instead believing personal responsibility plays a key part in addiction recovery -- an issue Luann also dealt with while shooting for the show, having gone to rehab multiple times.

As for Leah's allegation Andy does cocaine with the housewives ... Luann says she's never seen or heard about that, and adds it's not in his character.

LDL says she's now in the "driver's seat" with alcohol consumption and touring with a new cabaret show -- and insists you don't have drink to have a good time on 'Housewives.'

She further vouches for Andy, saying she doesn't believe he'd force anyone to drink like Leah's claiming -- a sentiment echoed by another former 'RHONY' star.

Dorinda Medley -- who appeared on the show from 2015 to 2020 -- tells us she feels terrible for Andy, and questions why Leah decided to come back for a second season of 'RHONY' and an 'Ultimate Girls Trip' if she felt so uncomfortable.

Medley added she'd jump at the chance to get back on 'Real Housewives' ... saying she's had nothing but good experiences with Andy and Bravo and she's gained so much by being on the show. She also said adults need to be held accountable for their own actions.

And, a non-New Yorker -- Cynthia Bailey formerly of "Real Housewives of Atlanta" fame -- also stood by Andy, telling us at LAX, she was never forced to drink or ever believed Andy was using cocaine as McSweeney claimed.

CB says she sympathizes with addicts, but adds people who know they have substance abuse problems need to make smart choices -- like turning down cocktails if they know they have a problem

BTW ... another former Bravo star, Brandi Glanville, is also threatening to sue Andy for an inappropriate comment he allegedly made.