The sexual abuse flashback was going to happen sometime during the manga, and I was just readying myself for it.
@Sylveonia I went ahead and tagged "Gore" and "Sexual Violence" for this manga. I wouldn't say there's a need to add a trigger warning for this chapter - it's a courtesy to some, but a spoiler to others. The "Sexual Violence" tag is more than enough and is doing what it's there for. Though frankly, I can understand why someone would want a trigger warning, considering that the girl was abused when she was a primary schooler.