That the thing, though. IT steals your memories, so the intimacy was supposed to bond the kids together forever so that they wouldn't forget one another (they do anyway), but to me it makes no sense, when Bev is the only one who's intimate with everybody and the boys aren't intimate with one another.

Then again, I think there could have been other way to get the same point across. They do a blood oath as well and I think that could have served a similar purpose if the kids had all mixed blood like the vikings and become bloodbrothers/sister and symbolically carried a part of each other in their veins forever.