OMG, he's fully buried in her and has to be pushing his tip hard to her cervix. That first hard pulse must have sent that sperm jet straight into her uterus. His potent black sperm was probably heading up her Fallopian tube to her waiting egg by the time he finished filling her womb. That is proper black into white breeding.
The best feeling of all is when she has a deep uterine orgasm in sync with you as you push your pulsing cock tip hard to her cervix feeding your sperm deep into her.