Let me take a moment to recognize this instance where these two knuckleheads aren't being profane

I wanted to draw an interaction piece and this is what I came up with. It's a couple months old and I've been slowly working on it. I may just print it out and color it with pencils. It's difficult for me to do digital art without a desk (hurts my back and knees too much), and when I sit at the kitchen table my parents look over my shoulders.
The girl on the left is Nina, who is Astro's little sister. I don't know if I've ever mentioned her on here before.

Constructive criticism is welcome and appreciated!

Art/characters c) me! Please don't steal!