Sam- Leaving water glasses everywhere. You need tons of water. No matter what you are always drinking water. I cups of course. Those cups never end up getting picked up and litter the motel's tables, counters, floors, and sometimes beds. He hates going around and collecting all of them.

Dean- You guys share a bed now. You always think he is taking the blanket so you always take it first leaving him cold. He doesn't mind that much just gives him a reason to smother you in your sleep.

Cas- How stubborn you are. You have to go on every hunt because you can help with every hunt. If you get hurt then you argue about going but never actually go. You always end up getting your way in little arguments due to this stubbornness.