Significado de "Just so you know"

Hey folks !

Does anybody know what is the meaning of the expression "Just so you know " ?
Here is a video from a serie call Everybody Loves Raymond. Raymond and Debora are discussing about the Tissues that Raymond has just bought. I think Tissue is a kind of paper that you use to blow your nose.

I think, just so you know means - "Só para você saber", em um tom bravo e agressivo.
What do you think guys ?

Here is the subtitles:

Debra:
- Fine. We`ll keep the damn tissue

Raymond:
- Don`t call them "damn tissues". There are gonna be our tissues and we`re gonna display them proudly. There are gonna be the official tissues of the house !

Debra:
- Okay, that`s great. Whatever you say, honey.
Listen, I gotta go pick up the kids in a few minutes.
And we`re supposed to eat dinner at your parent`s tonight, if they`ll have us over after your
Little "freak-out" .

Raymond:
- No, no. I`m not eating with those downers! I`ll make my own food right here. And I`ll decide to eat
Whatever the hell I want, all right ? Just so you know !
I happen to be a very good cook.

There are a lot of nice word and phrasal verbs, like:

pick up the kids
Damn Tissues.