"The truth is everything isn't great. It's not perfect," the reality star tearfully confesses to boss Lisa Vanderpump

“”Honeymoon’s over?

Just months after tying the knot, Vanderpump Rules stars Scheana Marie and Mike Shay‘s marriage has been shaken by an unexpected curveball.

In an exclusive clip from Monday’s episode, Marie sits down with boss Lisa Vanderpump and reveals the pair – who wed in 2014 – are having issues.

“The truth is everything isn’t great. It’s not perfect,” a tearful Marie says. “And I keep trying to act like everything’s okay. It’ll get better. I just keep telling myself, ‘It’ll be okay, and it’ll get better.’ ”

When asked by Vanderpump what the problems have been, Marie, 30, replies, “It all just started kind of around like Christmas time. I noticed, just a few months in, I noticed his drinking increased a lot – just more than drinking.”

In addition to drinking, Marie reveals to Vanderpump, 55, that Shay started to mix prescription drugs with alcohol – sometimes taking as many as five pills a day.

“You know it’s like, ‘Oh my knee’s hurting so I’m going to take a Vicodin, but then I’m going to have a couple of glasses of wine,’ ” Marie explains.

RELATED VIDEO: Lisa Vanderpump Is ‘Horrified’ and ‘Shocked’ by Costars’ Behavior

Vanderpump Rules

airs Mondays (9 p.m. ET) on Bravo.