It's deeply in a gray area I would say. There's a lot of unnecessary plot rape on the mc so the other guy could develop a his feelings or just straight up porn. The story itself is quite interesting, but I personally on a reread would skip couple of chapter because of unnecessary rape/smut scenes (not all, but most). At least the execution of this scenes shows, that they are clearly for fan-service, which is on the thin line for romanticising them.

Is this one a green or red flag ლ(´ڡ`ლ)