When I saw this posted video it made me think of something that really fascinated me when I first started having sex.
In sort of a "sex ed" class we were taught that "conception takes place in the dark". So while us horney teenagers were having unprotected sex, that semen we released and never saw, several hours later and in a very hidden place, might be creating a baby.
Until I started having sex I could always watch myself cum. But cumming during sex, it felt the same, but as a young kid for some reason since I couldn't see it I wondered if I was actually shooting cum too!
This posted video is sort of what ejaculating would look like if we had a small camera inside the girl's vagina and could watch our penis at teh moment we had our orgasm.
I know this is kind of analytical, but it was so different that it fascinated me when I watched it.