okay, i'm going to try to make this short: I've been with my girlfriend for 3.5+ years and we have great sex. I never have a problem getting hard and staying hard for her - it's huge with her and so hard i could hang a dozen wet towels off it! ANYWAY, I haven't been faithful with her for the last year because I'm young (19) and I feel like I should be having fun with my life before I get old. I know, I'm an asshole but I do love her I just get these urges you know!
Okay, so the last few girls I've been with I can't seem to get it up when the time comes. If I do get it up, get goes limp once I penetrate! I know I want to have sex, I really feel it and I'm all ready to go - and then nothing... The girls end up feeling like sh*t and I have the worst blue balls ever and I end up

! I don't know what to do, perhaps it's psychological because I feel bad, or maybe 'm just too used to my girlfriend's body?? Can anybody help me? Thanks
...Oh, I've got 2 Cialis left that a buddy gave me. I used it before with my girl and it got so big she couldn't handle it. Should I try it with these other girls or do you think my psychological bar would still prevent it?
SORRY it's such a long post. Thanks!