Here's a few that I've read/reading. I tried to look for some decent ABO without rape, or any other flags, But god I truly struggled to find one. Anyway here:
1. https://www.mangago.me/read-manga/sensei_no_sensei/
Cute fluffy ABO about a Beta school nurse and an Alpha teacher/ex-student.
2. https://www.mangago.me/read-manga/kasegimasen_kara/
Al......
