The accusations are flying — and perhaps the punches will be, too! Lisa Vanderpump has some harsh words for a number of her employees/costars in the Vanderpump Rules season 4 reunion airing Monday, March 21, as seen in Us Weekly's exclusive preview clip.

Footage from the Bravo series shows the Sur boss saying to one of her fellow cast members, "I was furious at him for lying to her."

The Real Housewives of Beverly Hills star, 55, also has a tense exchange with Stassi Schroeder, as the two have clashed ever since the former Sur server returned to the series midway through the season. Their issues stem from Vanderpump paying off Schroeder's ex after he threatened to release a sex tape.

"You and Ken [Todd] had gone to my parents and told us, 'You owe me 900 dollars,'" Schroeder, 27, says in the sneak peek. Vanderpump fires back, "Really? I was saving your ass."

Watch the clip in the video above, in which James Kennedy also threatens to slug Jax Taylor in the throat.

Vanderpump Rules airs on Bravo on Mondays at 9 p.m. ET.

Can't get enough of Us? Sign up now for the Us Weekly newsletter packed with the latest celeb news, hot pics and more!