American Dad S10 Ep 14 - M2F Transformation

Season 10 Episode 14 Stan Goes On The Pill
After having an argument with Francine about him never listening to her, Stan takes an experimental drug called 'Esterocillin' which will make him willing to listen. However, he takes more than the required dose, (on account of him not listening to the female scientist who explained the drug) and ends up turning into a woman. Upon learning there's a way for Stan to revert back to male, Avery deliberately withholds this information with the intention of sleeping with the now female Stan. They get as far as being in Avery's bed, but when Stan realizes he hasn't be listening to her at all, she immediately denies him.