Hello. New here. Loving owner of Kota, a Bullmastiff Boxer. At this post, 9 weeks old. Hope to learn from the community

First time dog owner, previously cat, dwarf hamster, betas, and goldfish. (in that reverse order

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Loving him to death. Wife's idea. Glad I chose to get him. My mom lives with us. She hates pets, but seems to be calm with Kota around.
A little scared of how he'll be when he's fully grown. 9 weeks old, and already 20ish lbs. Pretty powerful little pup so far. My main issues with him is the sudden dry humping (only my leg ;\ only when we walk), his habit of eating rocks and/or anything he can find - usually ends up being my shorts, biting/nipping (playful but getting powerful), leaping, and being scared of almost everything on 2 or 4 legs (unless it's female, human, and has treats ;\)
Other than that, very obedient, and we'll be putting him in puppy class soon.