Just for background - I have an angry, emotionally abusive ex partner and we split up six years ago. I have been with current partner nearly two years. Children know him, we've spent a fair bit of time together (he has a son) and they like and trust him. However, we don't spend every weekend together or anything like that - my partner and I usually just see each other when we're child-free as my kids have autism and they like to spend time just the three of us.
Anyhow - I have a work thing on friday and so my partner said he would collect kids from school and look after them (only til 5.30 pm) at my house until ex is due to pick them up (they are going to his for weekend so he would pick them up as normal on friday after tea). I had asked ex if he could pick them up from school as we always give each other the first opportunity when there is a problem. He couldn't do it as had something important on (fair enough, obviously). When i emailed ex to let him know current partner would do it, he said absolutely no way was a man he's never met (he has met him briefly and partner was extremely friendly and polite despite knowing what horrendous time I had with ex) looking after his kids. He's now arranged for his mum to get them and mind them til he can collect. That's fine with me - I like his mum and the kids will no doubt be pleased, so best case scenario all round.
However, am I right to think it's got f*ck all to do with him who I arrange to look after the kids whilst they would be in my charge? I am very very careful who I have to babysit - it doesn't happen often at all (only once or twice) because I arrange social and work life around the kids. However, I totally trust my partner and feel that it's up to me whether he looks after them when they would be with me, as long as they're happy with him. Clearly they know him and very much like him - if they had any qualms whatsoever, I would never even consider this happening.
I will obviously just go with ex's mum looking after them but I would appreciate your opinions on whether ex has a right to dictate this. Many thanks!