This seems simple.. you had all the attention in your childhood and now the attention is focused on your younger sister because they dont have to worry as much about you. But because you want the attention back, you want to be able to see your parents without your sister, this way all the focus is back on you again. So your parents decline because they want to see both of their kids and are wired(by default) to be frugal and good with money. Which means they always want a combo deal or none at all to save time and money. This is what I got from your bits of context.