My bf and I have sex a lot. (I’m 17 and he’s 18). Cause both of our parents r home we usually have sex in his car. Sometimes will be doing missionary in the car and he’ll be hard but then by the time we switch positions he’ll go soft. Like wtf? Then I have to jerk him off till he gets hard again. It’s such a turn off for the both of us. We’ve been together a year and have only been having sex for a few months. Is it my fault he’s going soft? No attraction? What should we do.