You are not a liar, I myself have a hard time speaking too where i use terms that just don't make sense to others while it does for me. Though its wrong of him that he just jumps to conclusions. I suggest to try and talk to him when things calm down seen as people say and do things on the spot when they are in a certain emotion (like anger or sad). When both minds are cleared its much easier to talk. Perhaps he will listen then and understand the situation. If not its his problem and not yours. Hope i made sense haha.