My ex wife has asked me to take our 11 year old son swimming. No issues we do this regulaly. But this time she has told me to take his 11 friend. I have never met this other boy nor his family. We dont even know if he swims. Due to safeguarding i have stated that i will only take both boys if another adult is with me. My ex thinks im being unreasonable and selfish. I would appreciate advice on this. Thanks