Hey, I wasn´t more than 20 when I first did it. And despite of that, I still consider myself lucky cause it could have taken much longer.
I hope your girlfriend is attractive, because as you know, overweight and cellulite can make it a struggle. A good deal of foreplay might help...
Might be nervousness too.. doing whatever gives ya a hard on, and then sticking it and staying in intimate touch with her body helps. Or whatever position you prefer. If it takes too long to get into action... -> dead.
Obvious hints.. but I´m not a specialist.
