Parents couch? Uh, what about your girlfriend's bedroom...? Why would you choose your parents couch over her bedroom? There's more privacy, and you can cum all over if you want. What kind of question is this? Canadien is right, you're thinking way too much. You got all the things you need. Why are you worrying about ejaculating on her parents couch when you could easily just go to her bedroom? This is such stupidity.