Is AUTHOR wrong in the post ? POST : I'm a PhD student. Aside from working on my thesis, I also teach, tutor, grade papers, hold workshops, participate in seminars, attend conferences, meet my supervisor ... All stereotypical grad school stuff. It's deadline-after-deadline.

My department has a brand new post-doc named Samuel, who came from Scotland. He does research with my supervisor, as well as teach courses on campus --- it's also really busy for post-docs. I showed him around when he first started here, and we became friends quickly, often having lunch together and playing video games on the weekend. Even our research areas are similar.

Around a month ago, Sam told me his graduation is at the beginning of November and he's traveling to Scotland. So he asked me if I can cover three of his lectures while he's traveling. I agreed, assuming that the department would pay me for my time: prep for three lectures can be 6-7 hours of lecture time, which would be probably at least $200.

But about two weeks ago, some of my impending deadlines started seeming worse: I have two workshops this week and next, and I have to create and submit a final exam by this Thursday. The workshops are for high school students and are about two hours each, and I have to create problem sets with full solutions, in addition to designing \~3 hours of lectures --- I've been working nonstop on this for two weeks and I'm still not done. And the final exam is for a class I'm teaching, I have to come up with fair problems and then time the exam to make sure it's fair to the students, which takes hours of trial-and-error. TBH I have not had time to even start writing the exam, and it's due for mass printing in four days (the sitting is in two weeks). In fact I'm feeling guilty writing this post because I have to get back to work.

Knowing all this, about two weeks ago I told Sam that I might not be able to cover his lecture. In retrospect, I should have said "cannot", but I figured my lack of sleep is less important than his graduation. So I told him to PLEASE look for someone else to cover him, ask EVERYONE he knows (other grad students, other profs teaching the same course, etc), and if he still can't find someone THEN I will do it. Looking back, I think everything I said was just an winded asshole-y way to say "I can't do it". He also told me last week that I would not be getting paid, so now it's just a pure favor that I can't afford to do.

But I told him all this two weeks ago, so I thought it'd be fair notice.

But he has not been looking for a replacement. He is just banking on me despite what I told him about my schedule. I just got a mass email from him on FRIDAY asking if anyone will cover him --- that's less than a week from the lecture. Why didn't he send this email sooner? And he only sent it to grad students (which is why I got it). There are several profs teaching the same class as him, so it would take less prep time for them because they have already prepared the lessons, but he hasn't asked any of them yet. I think he's been super lazy about trying to find someone despite how I told him I really don't have the time to cover him.

So now his graduation trip has become *my* problem. I think he should have actually tried to find someone --- especially given what I told him about my schedule --- but on the other hand, I should have just given him a straight "no" at the outset. I realize it's too late for me to back out, but I don't know how to tell him to *try harder* *to find a replacement* without being a dick.

AITA?

**tl;dr** *I told my friend I would teach three of his lectures while he travels back home. But I have a lot of deadlines that exact week, so I told him I will only do it if he can't find anyone else. He has not found anyone else, but I don't think he's tried very hard. I'm thinking of backing out because I'm way too busy.*