Marriage Of Covinience

It's a marriage of convenience
(All for the mission)
I announce you assassin and spy
But neither knows the truth until you add their daughter too
A telepath who can see between the lies

You like fake dating fics? Well this is it
Fake marriage with a special twist
A ruse that hopefully ends in the truth
Action, mystery, wholesomeness
And a bit of romance
And that's why you should give spy x family a chance