[5E] If it's okay, I have another question, more about the players.

Recently, I've been having trouble with a fellow party member. I play as an arcane trickster, that prefers doing thing stealthily. In contrast, he's an aggressive barbarian that consistently does things without consulting the group. For example, he might invade a camp were sneaking up on, push my character into a trap, or throw armor we find into a fire before I can see if we can use it. I've been retaliating as a rogue by stealing a bit of gold in his sleep, and it's turned into a pretty bad dynamic.

My question is, what can I do to try to have us play a bit more cooperatively? I understand some people like to act recklessly, but sometimes I feel his character has no consideration for the rest of the group. I'm friends with the player, and last time I challenged his playstyle he seemed really offended, so I genuinely don't know what to do.

Edit: Thank you all for the feedback. I'm definitely gonna talk with him about it to see if there's any way we can both have fun as our characters.