How can i make my boyfriend cum when i'm giving him a blow job?

suck on his head while masturbating him and playing with his balls.

Fondle with his balls? Learn the anatomy of male genitalia and find out the best ways to heighten his pleasure. And if push comes to shove, insert your pinky in his... It doesn't "make" him gay or anything despite what many people like to believe, it's just another area for stimulation.

I've got a few tips
Have him wrap his legs around your head
Slowly go up and down
Moan
Use your tongue
Swallow with a smile
Play wit the balls and lick them
Kiss the head
Lick the thighs
Rub the rest of his body
Deep throat it, like get his dick in your neck
let some cum fall on his leg or thigh and lick it up

And Never use teeth or go to fast

But Always give equal attention to the head, balls, and dick itself. Hope it helps

Ball tickling
Finger his buthole
Flick the tip with your tounge.

Get him to put his hand on the back of your head and guide you to do what he wants.

Play with his balls, suck on his balls, and also I suck and lick and go up and down for a while then use my hand in a jerking motion on his wet dick. When my hand gets tired, I use my mouth again and so on until he cums. tada!