Yes, sperm can sometimes leak out of the opening of a condom if, for example, your boyfriend leaves the condom on after his erection goes.
He was wearing a condom and he had asked to keep going. it harder for the condom to stay on — and really easy for semen to leak out.
Lots of questions, like: Can you get pregnant using a condom even if it doesn't break? And: Can sperm leak out the base of a condom? Yep.
Leakage: Condoms leaked in between percent and percent of sexual encounters studied, with percent of men and percent of.