Dunno if anyone's reported it, or if it's a bug or not, but the santa hat seems to include the sheep's "hair" fluff with it in the background regardless of who wears it.
If I had to guess, it was like that before too, but since it was just the cow and the sheep, the cow's ears hid the hair and it wasn't clear that it was there until we got two new "mobs" to "piston".
Bug 2: growing the boobs doesn't seem to increase the hitbox of the girls' breasts, making them hard to grab.
Bug(?) 3: the lv3 autopiston doesn't work great with anal, giving weak thrusts that don't make as much money. Some of the thrusts don't even register as thrusts, giving no money at all.