It wasn’t my husband’s snoring that made me nag him for years (I would have just gotten earplugs like other comments suggest), it was the lack of breathing. Waking up to a snore, and then hearing… nothing… nothing… nothing… nothing… GASP!!! is quite distressing. If WandowsVista’s partner is giving him feedback on noise, I am sure he’d be getting feedback on any lack of breathing.
Also, CPAP isn’t a clear win for a lot of people with apnea. My husband really struggles - even years after starting it - to fall asleep with a hunk of plastic strapped to his face, and middle of the night large air leaks that make the thing stop being effective are a recurring issue as wear parts get changed out and the straps have to be tweaked and tweaked to get the system stable again. For him, the reduced headaches (and lack of nagging from me) make the CPAP worthwhile, but I have known quite a few people who got the sleep study, got the CPAP, tried to make it work, and gave up.
You mention trying different masks, and none working. Have you asked about reducing the pressure? Or maybe switching to a BiPAP that reduces pressure for exhale? Nothing is guaranteed to help, but if you haven’t explored those options, might be worth asking.