This is something I've considered for a while. I grew up with Harvest Moon DS and have played a majority of the recent games, and one thing I missed in Stardew was the friendship levels with animals, especially brushing larger animals to raise your friendship faster, or the petting minigame a few of the titles had. I'm aware this may be a huge thing to try and program, and I dunno if anyone else is actually interested in the idea haha, but I thought maybe its worth putting out to see if anybody might agree with the idea.
Technically, you do this, already, it's just by right-click alone, instead of having to carry a brush around. A petting animation would be nice, but it might be better served with a suggestion, because I don't know if adding new animations is really possible.
