Since women are the gatekeeper to sex and men the gatekeeper to relationships, and since women can now retroactively annul consent to sex (even years after the fact), men should be able to retroactively annul consent to marriage.

I know this will never happen, but play along with this thought experiment for a second. Imagine the trepidation women would feel entering a marriage if a man could at any moment say 'I never consented to marriage, I was coerced by her' and then annul the marriage without recourse from the woman.

This may sound absurd, but it's no more absurd than a woman crying rape after consenting to sex.