Have you been raped yet and are ready to report on it to us? If not then you still have no room to remotely speak about consent and rape. Although you probably had to look up what oral sex was in the first place.
I am simply apply what left-wing people here have said about rape here:
(1) Having sex with a drunk woman is rape
(2) Having sex with your spouse is not a defense
(3) It doesn't have to be penis in vagina sex to be considered rape
Based on those 3 things going out for a dinner with your wife and then coming home and performing oral sex on her could easily be considered rape.
Is it stupid? Of course. But then liberal beliefs on sex are at least as stupid as the conservative beliefs they like to mock.