Lindsay Lohan's Beach Club Ambassadors

What Mike did was a lot worse than simply taking off his pants ...

"Oh Jesus Christmas!" -- that's Lindsay Lohan's first reaction when her beach club's general manager hits her up with a demand to talk to her ASAP about one of their employees.

And the reason behind the call quickly gets her blood boiling.

In an exclusive sneak peek at Monday's new episode of "Lindsay Lohan's Beach Club," the big boss and her partner Panos are discussing cuts to their staff when one ambassador gives Lohan more than enough ammunition to send him packing.

"I look stupid right now because this ass----," the club's general manager informs both Lindsay and Panos over the phone. "Mike is naked and I have like 30 people taking pictures of him."

"When I left everything was perfect and then I'm gone for only 30 minutes and it's like, what the f--k is going on," exclaims Panos. "Mike is naked and I heard that someone put crackers in his ass----, who does that?!"

Yeah ... that happens:

After Panos says actions like these leave the club being "disgraced," Lohan chimes in, angry as hell.

"And then who does that fall back on at the end of the day? Not even you, me," she says, once again reiterating the importance of protecting her "brand."

"This is completely unacceptable," she adds in a confessional. "Mike didn't just like moon people, he took his pants off. It's so disrespectful and it makes me look like a horrible person and that I'm not a good boss and that I'm not good at doing this job."

With the ambassadors' final days approaching, Lohan wonders if they all think they can just start getting "f--cked up" and "screw things up," before exclaiming Mike is "done."

We'll see if she follows through on her words when "Lindsay Lohan's Beach Club" airs Monday at 10pm on MTV.