I also have a hard time getting head. I have gotten laid by twice as many girls that have giving me head. My room mate has the opposite problem.
The most recent head was this summer. I was at my parents house for the weekend and riding around with a girl I used to mess around with. I talked her into giving me head while I drove. That was exciting, but took forever to get off cause I was concentrating on driving. Well she said she would take the load and just spit it out. Liar. She took half the load, pulled off, and I ended up nutting all over my shirt.
Thank god my parent's didn't notice when I got back home. That sh1t pissed me off.