What’s a Subtle Red Flag You’ve Learned to Watch For in Relationships?

What are some subtle red flags you’ve noticed in the opposite gender? Not the obvious ones, but the ones that don’t seem like a big deal at first but turn out to be significant after some experience.

For me, it’s being an only child. I’ve found that they can sometimes be spoiled and struggle with social dynamics, like making compromises or adapting to others. It makes sense since they didn’t grow up with siblings to teach them how to share, resolve conflicts, or live harmoniously with others.

What are your experiences with subtle red flags?