My DS is 3 years old and has asd. In the scheme of things this is a very minor problem but a problem nonetheless. 
Up until a few months ago, DS had lots of different colours and brands of straw cups that he would drink out of. Then, as things do, the numbers of cups started to dwindle, getting lost, etc and he just started drinking out of the same two cups that we were left with.
Over the weekend I bought some new cups (same brand, different colour) and he refuses to drink from them. 
Fair enough I thought, but I'm concerned that even if I go to lengths to make sure the retailer sends me the same colour that he's currently using, he still won't use it because the straw will be in perfect condition and not the chewed up one he currently has. He doesn't miss a trick this kid.... 
Regardless, I don't want him to get stuck using the same type/colour of cup as then what do we do in a emergency, i.e. if we lost it on holiday, etc.
Anyone else overcome this issue? Any ideas, tips, most welcome.