I hate it when they hold just the tip in when they cum. Fuck that, bury that seed as deep as it can go! So what if it doesn't look good for the camera. BREED HER DEEP!!!
Funny for me to say this BUT .. yes cock size matters but also .. for ALL men we tend to fuck strange pussy much harder .. and black and white is a common strange scenario .. I'm a black guy I can tell you for sure my wife would be responding to a big white cock stud the same way .. swallowing his load and letting him dominate