Who hasn't come across one or more shit weasels, I think everyone has. The comparison is excellent! All they do is ruin your day!
When I was teaching, I had a shitty weasel student ... one day she stressed me out so much that I had to leave the classroom to get some air because I thought I was going to throw her out, but I got some air ... a lot, calmed down and went back to the place, hoping to finish the hour soon.
When I was working as a commercial, I ran into a lot of fucking weasels, fuck! They make the day black, I tried to be as diplomatic as possible, finish quickly and leave, otherwise they would fuck up my day!