Your partner may be more than a liar, he may be a psychopath. Before you panic many psychopaths are not killers. But there are 5 or 6 personality characteristics they all to some degree. You Tube has excellent videos on how to spot a psychopath. I recommend watching a few of the 10 min ones.If I remembered the 6 traits I'd tell you but my memory isn't what it used to be. If this guy is a psychopath your only choice is to leave and never believe him again. Oh, they are also very charismatic, so if you do threaten to leave don't be surprised if he sweet talks you until you forgive him. Psychopaths don't feel empathy nor compassion. But they know what it looks like and they are experts at pretending they do. They are such great actors they can win Oscars if acting interested them.