Last Day at CBMS

Well today didn't go nearly as well as expected. In fact, it turned out to be quite tumultuous which really stinks. The first couple of periods were OK, I had to remove a student from both of the first two periods because of doing things that they shouldn't have down.
Fourth period is where it all "hit the fan". The students in my fourth period class are probably one of, if not my favorite class. They are good kids who have responded very well to me over the past eight weeks. I can joke around with them and just be goofy, and they like that. Today they decided to give me a "celebratoriral" shaving creme bath. So as the class started a number of them came up with shaving creme and got me pretty good. After I got doused with it I got up and left to clean myself off. I was upset so I decided to take a good walk for awhile (we had a Substitute in class today so he took care of the class). When I came back in towards the end of class I told the class what I thought about it. I was upset, sure, but what got me was how disappointed I was with the whole situation. Not just the fact that they got me with shaving creme, but also the timing of it. I would've been upset any other day, but couldn't they have chosen a different day to get me? I was looking forward to having them do their required work and then just spend the rest of the period talking to them and such but couldn't do it because of this.
The rest of the day was tough. I appreciated the words, cards, etc. that I received the rest of the day from my student but was still sooooo bummed about the time lost with this group. I know that there was no ill-intention or meanness directed to me at all but instead it was just a way to have one more good day with me. It just really stinks that this is a memory that I have from my last day there...it really does.
I think I handled it well. Discussed problem with students and did what I should informing my host teacher, but I know that doing that doesn't help whatsoever with my disappointment.