Raw unprotected sex on the sofa after wild night out

My buddy and his colleagues go out for dinner and karaoke partying and he asks me to come along. I successfully seduce one of his coworkers during that night out following her out to the bathroom when no one else notices fondling with her massive boobs, taking her number and exchanging all sorts of nudes at the KTV. At the end of the night she pretends to go back home but instead takes down my address and goes my apartment building.