My 18 month old has used a basic Tommee Tippee sippy cup since starting weaning, which he’s got on very well with. Today I started using an open Babycup to try to transition him onto open cups and it’s been a nightmare. He has tipped the cup over, soaking his highchair tray in water. He then tipped it over himself and his food and it’s gone all over the floor. I think he did manage to drink some but nowhere near as much as he would with the sippy. Is he at the age where he needs to be moving to an open cup or can I just stick to the sippy for now? I’m really stressed at the moment and having a load of extra mess to clear up is making it worse!