Why do both brother 's show affection towards Elena ?
Additional story lines revolve around the other inhabitants of the town , most notably Elena 's younger brother Jeremy Gilbert ( Steven R. McQueen ) , her best friends Bonnie Bennett ( Katerina Graham ) and Caroline Forbes ( Candice Accola ) , and their mutual friends Tyler Lockwood ( Michael Trevino ) and Matt Donovan ( Zach Roerig ) .