Is this possible with and iPhone 5?

Is it possible to not be able to receive texts from one person, after having a conversation with them for 4 months on your phone? I tested my texting with 2 other people and they both replied, I don't know it their not getting my messages or not. My phone stopped receiving messages a few hours ago but I fixed that, obviously.

No either that person is lying about sending you messages or you or possibly your parent blocked them from sending you messages
otherwise take your phone to the genius bar because i have the same phone and its never happened to me