May be this is a big problem asociated to erectil difunction problems .Because it isen't only asociated to a man that never can obtein an erection .
Of course when problem is asociated as my case , to premature ejaculation , you can't resolve it as simple as manteining allway a masturbation or sex with bride to avoid lost erection ( I mean mantein movement in the penis, because people loose atention ) say that because it is posible a man cum with such penis movement .
In porno actor film is custom see how they suddenly aply a mastusbation or hand job work to his penis to mantein better erection or don't loose it at all , it cause effect but I don't understand how they can later be fucking hard a girl with out cum (well ??? if some hand movement make them feel a sensation ) .
The best and quick is derivated of Sidenafil , allow you for a long period manteion an erecction , a help with the hands is usefull too , and in my case with premature ejaculation allow me cum once and mantein erection for at least a second continous fuck and cum , with out loose erection