Is this normal behavior with a boy??

Sometimes I really struggle with knowing why some of my littles do the things that they do. I wonder if it's developmental or if it stems from something that they have seen or had done to them when they were with their birthfamilies that is just unknown to me.

Josiah has been pulling people's pants down at recess and when he's home he's been trying to do it to the girls. It seems innocent...I don't think he means anything by that.

When we do time-ins, he sits in my lap and I hold him until our 4 minutes are up. Then, while I'm sitting on the floor, I stand him in front of me so that I'm still down on his level and we can look into each other's eyes and I know that he's listening and he will still be mad sometimes and he jumps all over alternating from one foot to another. Well, the past couple of days he's started movies his hips back to the front. I usually back up a little bit when he does this or he's putting his privates right in my face.

Today, when he was supposed to be getting dressed he stuck his butt right in Tracie's face without his underwear on. He's done this recently as well. We're really working on giving each other privacy when we're in the bathroom and keeping the doors closed while someone is in there (this is a huge struggle with him as he's constantly opening up doors and slamming them on people and he's so into what everybody else is doing that he's constantly trying to see who is in there).

He's really into telling everybody his bodily functions right now...I just farted. I have to go poo poo. And he's been burping left and right thinking that's just hilarious. I keep telling him that there are some things that people just don't need to know or hear and we're working on our manners. I know this part is a phase that kids go though. I'm trying not to make a big deal out of all of this so he will just go through the phase and be done with it, but there are some things I just can't ignore.