I am the wheel

I generally know when I am being used, and I'm sure it's not hard to tell for most people. It's the transactional relationship or episode.
In my younger days, I felt like it was a necessary evil in order to maintain relationships. In other words I did things for people knowing that they were having me do things for them because they know I would. Not the best plan when it comes to being regarded for more than my car, or having the opportunity to introduce them to other people, places or things.
Jake came home last night, or actually it was this morning and he asked if his Girlfriend could sleep on the couch because she was having trouble at home.
My question is, was she not having trouble at a more appropriate hour, could they have not come here earlier? No, because then I would have had the option to say no, and thus the being used part of our show is revealed. I understand that she needed a place to stay for the night, I merely would like to have actually had a say in if she got to sleep at my house or not.