Not every guy can ejaculate from getting oral sex.
I've never been able to at all.
I've had some of the best blowjobs ever from men who know what they're doing, who know what it's like to have a penis, and how to give some of the best blowjobs ever since they've had years and decades of practice.
This is a good thing OP since then you can have the other person suck on your cock for hours or even days!
Some of the men I've been with love to suck cock for so long that they can't close their mouths and that's hot dedication!
No I don't PNP at all but I do enjoy having sex with a male partner for that long without cumming if we have that much time to enjoy each other.
Fellatio or fellating someone is not "foreplay" even if some heterosexuals want to pretend that it somehow isn't actual real sex just because a penis isn't going into a vagina or a gaping anus.