
I think sleeping (and just sleeping) together is actually a pretty big step forward. It's closeness that isn't sex or passed-out-after-sex, and that's meaningful. Senpai is getting accustomed to Morinaga physically, whether he realizes it yet or not. Of course, I enjoy seeing them do more as well /wink.
I really want to see him waking up tangled together with Morinaga :)

I agree with you that it *would* be progress, and some nice intimacy... but let's be honest, no way are they going to just sleep. It'll be the same thing as usual: "You said you wouldn't do anything!" "I know senpai, I just..." "Damn it!!! I can't trust you at all" Morinaga ignores him saying "Stop" because tsundere yaoi logic etc.
OR Morinaga does just cuddle him but then senpai starts fidgeting and more "Damn it, this is all your fault you're always like this" and tsunderes them into doing it. Same old same old.

Obsession and desperation aren't necessarily love. It sounds unhealthy to me. Plus, he just laid a big guilt-trip on Henry about something that happened years ago. Not cool, Sam.
And what the sister is saying - stop seeing only Sam's good qualities or making excuses for his bad ones. Look at the real Sam and make a new assessment.
I'm not saying Henry is an angel, but once you put a person in the friend-zone (for whatever reason) it's hard and scary to try and shift them into a romantic partner. Henry's "love" for Sam was a fantasy dream that he clung to. The reality isn't going to be anything like that.
Thanks so much to everyone who worked so hard to bring us this story. What a sweet and perfect ending! Now we hope for a spin-off....