If you give an Emily a milkshake, she'll want a straw to go with it. She'll find her brother and ask for a straw. She'll realize there is no way she can drink all of said milkshake, so she'll ask for two straws so she can share with her brother. After all, she did interrupt his movie, so this seemed like the right thing to do.
While she's pouring the frothy drink into her brother's cup, a younger brother will come along and tell her he wants some. She'll give him a little glass.
By this time she'll notice that her glass is less than half full. She'll decide to make a little more for herself. She has already put the blender away so she'll try to put a scoop of ice cream into her glass and stir it. It doesn't work. She'll haul the blender back out. When she's finished blending, she'll need more milk, then she'll need more chocolate syrup.She'll get out the giant chocolate syrup bottle and start squeezing. She'll squeeze soooo hard, that the lid comes off. Before she knows what happened, globs and globs of chocolate syrup will have come out. She'll have to add more milk and more ice cream to cover up the overpowering chocolate taste. She'll blend it again. At this point her younger brother will see that she made more, and even though he hasn't finished his, he'll want some. She'll pour a little into his cup.
When She pours her milkshake into her glass, She'll realize she made to much. Again. She'll shrug.
She'll clean up the mess she made (which was very large). Her younger brother will start whining for her big glass, so she'll sneakily put it in the fridge and tell him, "All gone!", until he goes to bed.
When he's finally in bed, she'll sit down to relax and enjoy her milkshake, (which still tastes too chocolate syrup-y).
When she finishes, She'll notice her fingers are sticky. Feeling sticky will remind her of her favorite milkshake.
And chances are, if she makes a milkshake, she'll want a straw to go with it.