During sex, it’s not standing for me long enough and I don’t manage to cum, when it’s already soft. It seems like everything is fine at the firs moment in foreplay, but when some time making out passes, then it starts – it gets soft although I’ve not finished yet. What do I do? (Male, 19 y. o.)
There might be various reasons. You should separate issues about loss of erection before and during sexual intercourse.
The reasons why erection is disappearing before intercourse might be connected to too big excitement, prolonged foreplay during which your sexual excitement goes away. Some other reasons could also be various psychological factors, etc.
Loss of erection during intercourse is more connected to insufficient stimulation of penis. Most often in such a situation the reason is different pathologies of foreskin. It would be recommended to consult with specialist about such problems!