4. OPEN
The mutants in the Brotherhood house weren't open. They didn't tell you anymore than they had too, they didn't let anyone in unless they had too, and they certaintly didn't go around telling their house-mates what was going on or how they felt. If you wanted to know, you had to figure it out on your own. Todd was good at that.
If Pietro was quiet and had been in the same place for more than a few minutes than you knew that something was wrong, normally something that had to do with Magneto or Wanda. If he was just a little pensive, well, than you better high-tail it out of that house because he was going to go on either a cleaning spree or -and this was more likely- a pranking spree.
Just like you could tell that when Lance's head-aches kicked in, you better shut up and find someway to calm everyone else down or you wouldn't have a house. Todd also knew that on days Lance was hanging around the phone you better not have any calls that day.
He was used to having to find quirks and small tid-bits of information to figure out what was going on, having to read everyone just to figure out what was going on in the lives of the other mutants. Not being able to just look in someones eyes and know what they were feeling.
Kurt's eyes were like looking at an open book. It didn't matter what the furry mutant said, you could always tell what he was really thinking, really feeling, by looking in his eyes. Sure, that made it easier to tell when he was happy with you but it also made it easier to tell when he was angry or dissapointed. And Todd just wasn't sure whether he was ready to give up having to look for those little quirks to know what was on everyones mind.