Haha based on the close proximity of their faces when senpai imagines Morinaga is there I’m guessing rather than saying “I love your scent” in his normal voice Morinaga actually whispers it and senpai is currently very horny so of course he’d unconsiously let out a moan. I mean, I even got some goosebumps myself ε=ε=(ノ≧∇≦)ノ
Imagine being very turned on and someone you desire whispers in your ears they love your scent, like damn senpai I don’t blame you for not being able to control yourself
I think Morinaga whisper just "Senpai" and then Souichi reminder his dream about Morinaga saying him "I love your scent".
Yes I think that's exactly what happened.
Oh my. That was enough to make Senpai make a sound? Damn he's got it bad. lol I just hope that Tadokoro doesn't come home like "HaHA I came home early!" and end up seeing Morinaga and Senpai in the middle of doing it. That'd be too much awkwardness for me.