I served them lemonade in unclean glasses
Why did you avoid using clean cups?
I meant that I just cleaned the glasses roughly with a little soap
That is still a bit dangerous to do, as it becomes unsanitary when glasses are not properly washed. It is disgusting and you should have just used a fully clean glass.
Haha. Please. I checked the glasses on the inside and washed them on the outside thoroughly. Everything is fine.
You should have made sure the glass was clean before using them, and that means doing more than just looking them over. It is going to hurt your friends if the glass was really dirty, they could get sick!