Real Housewives of Beverly Hills' peacemaker Adrienne Maloof had a ringside seat to Kyle and Kim Richards' vicious, upsetting limo fight on Thursday's season finale.

"It was very difficult," Maloof told during a visit to our NYC offices. "The most difficult scene of the whole season. It was emotionally and physically draining."

In the shocking brawl, Kyle accused her visibly drunk sister Kim of being an alcoholic and mooching off of her and husband Mauricio for money; a weeping Kim inexplicably yelled "You stole my f***ing house!"

"I did what I could to prevent [the fight,]" adds Maloof.

It was later revealed that Kim spent a week in rehab before checking herself out, and that their kids were trying to broker a truce between them.

Just as exhausting for the cast? Taping the epic reunion special. Hear what Adrienne -- and costar Taylor Armstrong -- have to tell Us about all their showdowns with Kim, Kyle, Lisa ...and Camille.

Watch the exclusive interview now!