How can you tell if your paranoid or your bf is a liar?

why would a bf (we re both in our thirties) lie about stupid things, like where he got stuff from, places we re going to go, that don;t actually end up going, the state of his finances (ie making out hes loaded when really his ex wife had to give him an allowance when they were wed to stop his excessive spending). He s lived in his flat a good eight months and claims hes not had a woman there (let me state now, i wouldn't care either way) but he says he hasn't yet he's got a positions dice out in a bowl under the bed, now he can't be using it by himself and in five months he s never mentioned it to me or tried to use it with us. I mean why would you unpack that and leave it open in a bowl under your bed, its not like he's the type to randomly take girls back. I just can't make sense of it and I m always feeling paranoid and stupid, if he lies about things like this, even down to making up intricate stories about where he got my gift from when it turns out it was simply bought from our own city. I have children to consider and don;t want to end up with someone untrustworthy, or worse still, a compulsive liar. I know his finances are bad, but he won't admit it and insists on flashing cash on things for himself mostly, but we haven't had even a night out in about five weeks, he wants/expects us to hang out n eachothers places and watch TV, I wouldn;t mind if he made events of it or did little romantic free things to make up for it but he doesn't. I just feel undervalued, I tell him how I feel and he argues his case and nothing changes. I m ina rut.