Most times, peeing with company is a fear or excitement response. My Aunt has a little dog that does it every time. When your company comes, you need to tell them not to make a big deal of him. Basically ignore him until he calms down, then take it slow from there. When I go in my Aunts house, Buddy gets so worked up. I have to pretend he's not there until he's calm. Even then, once I start acknowledging him, I have to go REEEEEAAALLLY slow, otherwise he just winds up again. Other than that, if he's a long-time family member and is just starting urinating about the house, something is off and disrupting his world. Pay attention, is it related to thunderstorms, loud noises, loud tv, a significant change in the household? If you can find the trigger, then you can hone in and hopefully find a solution. Of course, this is all after ruling out bladder infections or other medical conditions.
Good luck. Take him out as often as you can and remember, try not to scold him or make him feel bad about his accidents, it could cause it to get worse. If it is caused by anxiety, excitement or fear, it could cause it to spiral out of control!