Replying to Sexual favors as a form of payment

So theres this hot girl in my chemistry class that I happened to be put into a group with to do a project. Anyway, the other day I get a text from her saying that the group is coming to her house to work on the project, and that I should come. I really didn't want to work on the project, but I went anyway because this girl is fuckin hot. When I arrived, I noticed that none of the other group mates were there. I asked her what was up, and she told me that she wanted it to be just me and her. I told her I didn't want to do the project, and she said that she would do the entire thing if i railed her up the ass, smackers and all. So we headed upstairs and got straight to anal. I exchanged sexual favors for a reward, so am I technically a hooker?