I was an RA in college and I was terminated from my employment for saying inappropriate things to residents, such as making inappropriate jokes or using curse words. I also hooked up with 2 residents, which was against university policy. Will this affect my chance of a top secret clearance?
That depends on how long ago it happened and whether there are other instances of the same behavior and/or terminations in the past or more recently.
This happened in 2012-2013 school year, when i was a junior in college. This incident was isolated to my RA job. This has not happened again since.
As long as there is no recent similar behavior then it should not affect your eligibility as long as you are totally up front and forthright about it on the application and during your interview.
Concur with Marko. Be blunt with the investigator. Lay it out there so you do not risk a "lack of candor" finding. That is a tough one to mitigate. If they know you lied about something, and less than full disclosure vice full disclosure is viewed as a lack of candor, the assumption is you will lie again. If you make an adequate case for immaturity, couldn't resist temptations of the moment...unlikely to repeat itself (that is key), regretted (key) then you should be fine.