We use a little tempered glass cup - like a shot glass! And he loves drinking it from that. Didn’t like it in anything else 🤷🏼♀️
Yes try a sippy cup, also yet boil some apples and try give him the water from that. Not to much or to often tho. Also cucumber and watermelon as it's basically just water isn't it xx
We do drinks in an open cup and he seems ok with it although usually only has a few sips then steals the cup and spills it everywhere 🙈 have you tried different types of cups? Watery fruit and veg might be good too - cucumber sticks, melon etc x