Went for lunch at my parents today and forgot DS's tommee tippee sippy cup. Gave him some water from a plastic cup with a straw and he took to it really well. In fact, he bloody loved it! Got me thinking that I might try him with a fruit smoothie with a straw too (at the mo I just spoon feed it to him). Is it bad for his teeth though? I've read on the back of fruit pouches that frequent sucking isn't great, so it must be the same with a straw? Help me out wise ones!