Well, we went to the zoo yesterday, and after we left he wanted to walk around by the little lake they have where you can paddleboat and stuff. I got some rocks in my shoes, so he suggested that we sit down on a bench so I could get them out. I was about to take off my shoe, when I saw something floating in the water. I went over and looked, and it was a dead baby duck, and then I got all sad, so he suggested we walk away (apparently he was about to do it too... but couldn't with the dead baby duck) Then we were going to walk out onto this little pier thing, but it was gated off (his second option), then we were going to try a bench on a little outcrop, but this was already occupied by a homeless guy (option 3). We keep walking, and he finally says, "I want to go sit on that bench" which was unoccupied and kind of out of the way. We're sitting there watching the ducks and stuff, and he's like, "Hey, you wanna spend forever with me?" I said yes (duh) and then he said, "Amy, will you marry me? Here, I'll do this thing" and he got down on one knee. 
I was caught totally off guard, but there were so many signs that I should have picked up on! His insistence on going to the zoo, convincing me to wear a cute dress, his sister on the phone telling him to "make sure he has the right accessories" when we went, etc.