The poor children were hit first,,as a lot of children do take the brunt of an acrimonious split/divorce.
They weren't going to Norway with Colin and the girlfriend,,nor were they going to remain with Colin for most of the time,only allowing Sheila visits.
Neither was Sheila going anywhere convalescing,at the behest of her parents. When no support or backing was coming forthwith from Neville,,he was the 3rd victim. Which left the two women battling it out in the bedroom.
Just where Jeremy comes into this,,I don't know.?