<human>: So, for some context: 

I/my family have two dogs, a miniature poodle who is now 10, and a recently rescued chihuahua, who is maybe around 6. Both are males. We recently rescued the chihuahua after my other dog passed away after having him for 2 and a half years.

My grandparents have an even smaller poodle, who is maybe 7 (also male). This dog is obsessed with my poodle, wants to be his best friend, and always be next to him. For years, whenever my grandparents went out of town, we would dog-sit for them, and we never had a problem. Their dog is really yappy, but there are never any other big problems. 

We recently had to dog-sit for them, and it was the first time that their dog was over at our house with our new dog. Well, their dog was actually being fairly aggressive to my chihuahua (who I consider my dog over the poodle, who is really my mom's), and I was very upset with their dog. He was growling at my dog a lot, in addition to his usual yappiness. By the end of his stay, I was fed up with behavior, so I decided to enact some revenge. And YES, I know I am taking revenge against a dog who maybe doesn't know what he's doing, but he should know not to be aggressive to my dog on his own territory. 

So what did I do? I took a bright pink sharpie and colored the tips of his poofy tail pink. I also gave him several squinty-eyed angry looks so he really knew what I was doing. I sent that little yapper home with a very beautiful pink tail. 

NOTE: I only colored his tail, not his skin, so I didn't harm him.

Can you provide a brief overview of the text?
<bot>: Had to dog-sit grandparent's yappy dog who was aggressive to my dog, colored his tail pink in revenge.