Kyle Richards and Yolanda Foster said goodbye to their daughters on Tuesday as the two young reality TV stars headed off to college.

"The whole dynamic of our home changes with each child that leaves," Richards said, "I just want to run after her."

Richards' sad words reflected the entire night, as both Richards and Foster took their respective daughters aside for a last, heartfelt adieu. Richards' daughter, Alexia, went off to attend the University of Arizona. Kyle, her husband, Mauricio, and Alexia had a light-hearted, but tear-jerking night together.

It was also a night to discuss responsibility. Richards and Mauricio tried to set a budget for their daughter to aim for. At last, they compromised with a $1800 a month spending limit. Hopefully, Alexia will be able to keep within that limit for college.

"She's gone from a little girl living at home to an apartment," Richards commented. "A part of me wants her to finish at U of A, but the twisted part of me wants her to move closer to home."

'Real Housewives of Beverly Hills' costar, Yolanda Foster, also said goodbye to her daughter that night. Bella will be attending New York University.

Before she left, Bella wanted to mend all fences with her mother, so she wrote a beautiful letter apologizing for her DUI. 'The only thing I want is to gain back your trust," Bella wrote. The reality TV celebrity's daughter went on to emphasize that the mistake she made "doesn't define who I am."

'The Real Housewives of Beverly Hills' will air next Tuesday at 9 pm on Bravo.