I met a girl and we dated for a month and one day went to her cottage outside the town had some alcohol and were about to have sex, i put a condom and my erection got weaker,I entered her few times, but then it came out from her itself few times, probably because was not erect enough, she took the condom off and did oral and i came. I was ashamed, second time same thing happened it was in few days. i came just right before i entered her. Do you think its a disease? at home i can maintain erection for as long as i want . Especially when excited. Sometimes it can be weaker if excitement disappears, but if concentrate it comes back to strong erection. Maybe it some kind of vessel disease? My girlfriend looked disappointed and didn't say anything, i felt even worse after this.