"Suck my milkmaid, Sarah Fray"
I will give you all of me.
Just leave your lover, leave him for me

The story:

I love Sam Smith, I believe he could do no wrong. This is what I tell
myself when I realized I've been singing "suck my milkmaid, Sarah
Fray" instead of "Set my midnight sorrow free" for the first 6 months I
listened to "In the Lonely Hour" during my commutes to work. I
always wondered who this milkmaid Sarah Fray was, what was her
story? Why did Sam write a song about her? or I figured it was code
for something sexual. And yes, I definitely sang it with conviction in
front of multiple friends, haha! Oh well, you win some, you lose some.
To my defense it totally sounds like he says that!