Well I think there probably some reason for Colin wanting the twins living with him and the school reporting they were worried . The letter he wrote to Neville was more of an indication than anything Jeremy said .
Yes. Guilt for walking out on a new mother who wasn't coping was probably one of them. Colin, as his letter clearly outlines, clearly had no more liking for the Bambers -OK, mostly June, as a Christian- than she had for him, as an out of work? atheist/agnostic?