Hello!

My(29) bf (28) lives with schizoaffective disorder. I’ve noticed around the same time each day, around 3pm - 4pm, he gets up &amp; walks back &amp; forth in the bedroom talking to himself (but no voice comes out). He does hand gestures and sometimes laughs to himself. 
Throughout the day he’ll every so often talk to himself and if he notices me start to look towards him he’ll stop sometimes, but recently he doesn’t stop. During the day and when he laces back hin forth he’ll like raise his eyebrows up, look around, laugh to himself, shake his head yes or no etc.
He says he feels like he can fully trust me. He takes his meds morning and night religiously, which also makes me question why he’s still having hallucinations?
I don’t know what to do when he does these things. It does scare me or anything, but I want to support him to best I can. Last night it seemed he was arguing with a voice in his head so I interrupted and we went out and got dessert which he thanked me for doing. 
I just don’t know if this is therapeutic for him to do, if it’s destructive for himself, or what. I want the best for him. 

Sorry if I sound completely ignorant, I’m brand new to this &amp; want to be able to be there for him. :)