You spend the night at your girlfriend's house but wake up to her little sister "um, my sister left for work an hour ago... you need to go." You ask her why she's in her underwear and she giggles "it's my house I can wear what I want... does it make you uncomfortable? Oh my gosh you like it don't you?" She tells you her sister said you have a big cock and she wants to see it. You're taken aback, all of a sudden she's coming on to you HARD. "Don't pretend like you don't want me... if you didn't you would have just pushed me off you." She starts to suck your cock, dirty talking about how her sister's pussy juices are still all over it from the night before. "I want to know how my pussy feels compared to my sister's" she moans and starts begging you to cum inside her but at the very last minute she gasps "I forgot to tell you something really important.... I'm not on birth control AND I'm ovulating!" In the heat of the moment, not thinking about the consequences, you cum deep inside your girlfriend's little sister. Oops.