He currently drinks formula milk out of MAM bottles with teats and has water with meals out of a sippy cup (no valve). NHS advises to stop bottles at 12 months due to tooth decay and speech delay. I don't know that he'll drink his milk out of the sippy cup as he normally throws it after a few sips. Is a bottle with a straw taking a step back or is this fine? I've tried a 360 cup but he just bites it. Don't want to attempt an open cup just yet because I'm confident it will end up all over him.