I agree with Babybaillie it depends how ill. I would still let LO go if its just a cold, or something simple, and he's still in good form, being himself, but anything more than that then no. It does cause arguments as ex says he's his father and can look after him just as well as i can, but i wouldn't leave him with anyone when he's ill, and usually if he's not himself, he just wants his mummy anyway. Anytime he has taken ill at ex's, he has came straight back cause he's been crying to go home and for his mummy.