My LO is 14 months and transitioned himself off of bottles and onto sippy cups. He was taking 1 of his bottle feeds via sippy and chewed all of the nipples off of his bottles, so I just gave him his sippy cups instead and he took them. But I had to buy more, because he was also chewing the tops off of those. This time I bought cups for 12 months +, rather than the starter ones and he won't take them. He throws it at me the second I give it to him. The only difference I can tell is that he actually has to suck a little more, rather than the liquid just flowing into his mouth. Any tips for getting him to drink out of them?