Help no judgement just advice

Hi so I have had my.male cat since he was 7 weeks old he never once peed on things.then about 6 months ago he started doing it out of the blue he only does it on any clothes that are left on the.sitting room.floor even tho his litter is done every week and my girlfriend keeps loosing her tempter and lashing out at the cat this has to stop wht can I do ....