While this may not have been my favorite - it still rates pretty high up there. The twins are still working in same research lab, but this time they're greeted one day at work by Brad and Caleb, two of the lab's finest techs. That's only the beginning of course. It gets a lot better from there. The guys convince the twins that they're researching the mating habits of birds. Brad tells the twins that if the girls do sex stuff in front of the birds, they will start to mate. The twins begin to do loads of sexual response therapy in front of the birds that eventually lead to fucking Caleb. It's all the sex that you can handle this season, all in the name of science! Check out the rest...