They always dump their kid with me!

My older sister is married and has a two-year-old child. She always calls me whenever she wants to go out and meet her friends, and I don’t mind because I adore my niece, but it is starting to feel as if I am being taken for granted by her and her husband. They know I’m single and always assume I am free to babysit irrespective of whether I may or may not have plans. They recently asked me not to go on holiday this summer, saying they wanted to take some time off and would really appreciate my help looking after their daughter. I love my sister a lot, but I am now starting to feel a little used. What should I do about this?
She is your sister, and you should be able to have this conversation with her even if it is awkward or difficult. Parents are supposed to take care of their children because that is what parenting means, and to assume that you are at their beck and call is wrong. It will also lead to unnecessary friction because we always have limits when it comes to dealing with family even if we like to think these limits don’t exist. This doesn’t have to be an antagonistic conversation though. Tell your sister why you are frustrated, make plans the way you used to, and inform that when you can’t babysit until she gets the message and begins to treat you as an individual with a life of your own.

Is it okay to have sex on the first date? I really like this person and I am tempted to but don’t want to come across as too desperate.
There are no rules when it comes to consenting adults. Why not go on that date, see how you both feel, and talk about it if it makes you both understand each other better? It is your choice and your body, so you should be able to make that decision based upon how you feel.