The alarm goes off across the room. You're awake. They're not. An alarm that isn't even yours pulls you out of deep sleep, and then you lie there listening to it snooze, again and again, while the person beside you sleeps through every round. That's not a sleep problem. It's a resentment problem.
Collateral Damage
Their alarm doesn't wake them. It wakes you, 60 to 90 minutes before you ever needed to be up. You become the human snooze button.
The Cortisol Spike
A blaring alarm spikes cortisol the second it goes off, for the person it's meant for and the person it isn't. You both start the day in fight-or-flight, before either of you is even conscious.
The Morning Fuse
After a night of their alarms, everything they do annoys you. Bad sleep doesn't stay in the bed, it becomes the fight at breakfast.