I misread the HH and somehow thought that we had 3b and CO flatted the 3b and BB had 4b, but I see now that it is not the case (UTG just limped).

But still, when we flat we should expect CO to call, right (odds and all)? Do we really want to play AA multiway post-flop sandwiched between a 3-better and a caller?

Please explain why it is such a good spot to be in.