How about I ask my girlfriend for a blowjob and make our relationship all about sex now.
why do you want to make your relationship all about sex?
I think it's a completely acceptable and sane.
You have to understand relationship is not all about sex. You're treating your gf as a sex object which is wrong.
Sex isn't a big deal. If she doesn't want to dump me, it will happen.
If she cares about you, she would not want to leave you. You should care about her enough to not objectify the person you are in a relationship with. You should communicate your needs and desires and come to a compromise with each other.