Well good, they can be guarded and shy together. Even if at first that just means they sit silently in a room together and ponder over what the other is thinking.
If Liam ever misplaced anything, he should ask Cian since that's kind of his speciality anyway. Seriously, sometimes he can't sleep because he'll get images of an object that seems somewhat important or valuable and he'll have to get up and go collect it or try to return it to its rightful owner before he can sleep.