He still cares about being a failure, taking care of Ami on his own, and getting his rocks off.
Also I recommend reading my original post that started this, as I literally brought up the sister point:
It's from Niki's 'Sisters' Invite event. Ami told him that she had sisters now, in it.
Keep in mind, Sensei still told Niki not to get involved with Ami, and even the Sekai Narrator was telling him he knew why Ami called Niki and that he was taught better in Niki's last event:
Ami actually wants a Parent. Especially a Mother. Sensei knows this, because he does too.