Antisocial (3.5e Flaw)
From D&D Wiki
You have some sort of social awkwardness or hostility which makes it hard to work with you. You can still function in a team, but less so than most.
Effect: You take a —6 penalty on Bluff and Diplomacy and may not place ranks in either skills and nonhostile creatures start out one step less friendly to you (to a minimum of unfriendly). This is only the starting mood, and may change over time. Additionally you may not take the Leadership or teamwork based feats.