(Piers would notice that I wasn't next to him all night, I wasn't sleeping next to him even though he was sleeping in my bed. I wasn't next to him when he woke up in the morning)
(Piers will find that I haven't appeared next to him all night, I haven't slept next to him, even if he's sleeping in my bed. I wasn't next to him when he woke up in the morning)
Piers will find that I didn't appear next to him all night. I didn't sleep next to him, even if he slept in my bed. I wasn't there when he woke up in the morning.