Intimacy issues

So me and my so have always had issues when it came down to our sex lives. Don't get me wrong we do have a great time but we don't do it as often as we should. Once a week seems to be the most we get. I started to think it was me but he says it's not he completely attracted to me it's just he's lazy. What can I do to get him interested more or get him in the mood more often then once a week.