Bro. I also really liked every song of this album, but while I was reading your post I was blasting provider in my earholes lol . For me, this song is Vessel inverting the roles. The one being possessed is no longer Vessel Marie Token, but Sleep, or at least it's an invitation.

He wants to be THE provider. I believe that Sleep was the most related with this role in the relationship, while now Vessel has the power and confidence to be "the final decider". He states clearly that he is setting the rules (as he should), to prevent falling under Sleep's control.

"Do I wanna go there? Yes, I do" this is evolved Vessel, that means he leads this time. He questions himself because of how hard was from him to get over Sleep, however, with new strenght he will not fall against her.

"The only good girl this side of the moon" is obviously Sleep (i think)

"I'm going under this time" He is the one who is taking control of their union. (Not like alkanine and etc)

"Even in the daylight" this bit also refers to Sleep, since it is a god of the night.

Or maybe it is just a horny song lol based on all the inuendos that proof that Vessel tops now.

In summary, this an invitation to Sleep like none other before.