My family has recently gotten a puppy, about 5 months, and he's still very much a biter. He's a small dog so it doesn't generally hurt all that much except for when he's really hyper.

Today, I (16f) was watching TV with brother (19m) when the puppy got playful. I played tug of war with him for a while before getting tired and giving him a toy keep him busy. Unfortunately, it didn't and he kept trying to play with me by nipping at my hands and arms pretty hard. I was telling him no but he didn't stop. When he bit me particularly hard, I shut his mouth with my hand and said "no" again. My brother then paused the TV and said "I don't want to be here for this." And my first reaction was to get indignant and respond, "well you're not the one being bitten." He didn't say anything for a few moments after that so eventually I asked if he wanted me to leave the room. He said yes so I did.

I can't help but feel a little annoyed with him but I'm struggling to figure out why or is it's justified, so I thought some outsider insight might help. Thank you for taking the time to read.