My dcs' dad is moving away, to somewhere 3 hours away on a good day, up to 5 or 6 depending on holiday traffic, weather, roadworks etc. He wants to still collect our 6 and 8 year olds on Friday after school and bring them back on Sunday for 6pm. He also wants to change Christmas arrangements to having them for a whole week, rather than one parent have Xmas Day and the other have Boxing Day. He currently has 3 weekends out of 4 and I've always been very cooperative, but I'm not happy with this as it's such a long journey. He says he has parental responsibility and noone can stop him from collecting the children from school and taking them. We only have an informal arrangement, which my solicitor outlined in a letter 2 years ago. No court order. Are his requests reasonable?