What are the biggest problems during first sexual intercourse?

I want to specially point out one men’s failure during the first sexual contact, it is inability to perform sexual act – lack of erection. Second would be too quick (premature) ejaculation. It might happen without even starting intercourse, with first move or just right after it. Normally the length of intercourse should be 10-15 minutes from first moves till ejaculation, because it’s the average time needed to satisfy the partner. Third problem is disappointment in sex partner. If to analyze the reasons of these problems, there has to be mentioned stress, worries, too big excitement, hyper sexuality, unsuitable conditions, uncertainty, fears, etc..

What are the consequences of stress during first sex?
Is first contact always pleasant?