Lori Loughlin's Daughters Olivia and Isabella Not Returning to USC

Lori Loughlin's daughters are not letting USC decide their fate, because they will NOT be returning to the University for fear of bullying ... sources connected to both daughters tell TMZ.

We're told 19-year-old Olivia and 20-year-old Isabella have made the decision to withdraw from the University. Our sources say they have the full support of their parents, Lori and Mossimo Giannulli, both of whom have been indicted in the college bribery scandal.

Our sources say the family feels certain, if the girls went back to USC, they would be "viciously bullied." So, the decision has been made.

As we reported, the indictment claims Lori and Mossimo paid $500,000 to have their daughters designated as recruits for the crew team at USC ... despite the fact they did not actually participate in crew. Mossimo allegedly sent action photos of their daughters on rowing machines to Rick Singer, the ringleader of the alleged scam, and he presumably sent them on to USC.

We're told Olivia and Isabella never really wanted to go to USC. Our sources say they liked the concept of school principally because of partying, and had their sights set on Arizona State University. That's why Mossimo sent an email saying he wanted to get his daughters "into a school other than ASU!"

Our sources say Olivia in particular "is a mess, despondent and feeling like it's the end of the world."

We're told Olivia and Isabella will "lay low" and not try and enroll in another school ... at least not for a long while.