honestly, anytime someone is wearing a cross or mentions they are Christian or religious, I assume they are unsafe and likely have some kind of bigoted views. To be fair, I think most people are bigoted to some extent, we can hardly escape the acculturation that comes from growing up and living in a society that has heteronormativity baked into it.

I know for sure that not all Christians or religious folks are anti-LGBT+, but where I live it's fairly predictive that if someone is religious they're also more likely to be conservative and have reactionary views on topics like science (e.g. more likely to be creationists, anti-vaxxers, etc.), gay rights, trans rights, etc.

Ill list a few telling signs:

1. Saying "gender ideology" or "biological gender" (which is absolute nonsense)
2. Asking bad faith questions (such as demanding you debate your rights)
3. Complaining about "woke" people or "radical leftists"
4. Saying "I support Queer people buuuuut..."
5. Implying the existence of Queer people is new, like gay marriage only appeared two decades ago
6. Saying "I just don't understand" and then making absolutely no effort to understand
7. Complaining about Queer people whenever they're visible (such as in media or on the news)
8. Men speaking on behalf of Women in claiming that Queer people are a threat to them (to justify allowing cishet men to "inspect gender")
9. Saying "I don't want my children exposed to that" (they expose their kids to cishet romance)
10. Saying "Leave my kids alone" (they think they own their kids and can force them to be a certain way)
11. Trying to sow division (ex: why do all queer people need to fight together when they can ~~be divided and conquered~~ "speak louder alone")
12. Saying "I just believe in traditional marriage and a traditional family" (nothing is traditional about the nuclear family)

That in 2025, they're still obsessed with the idea of a person who is offended by differing opinions and wants to ban them, not recognizing the irony.

Sometimes open discussion might be useful, but with where the world is at, this is usually code for the person not liking gay or trans people, women, or minorities and wants to be able to say slurs openly without consequence.

they insist on using the archaic "he" as a generic pronoun instead of the much more inclusive singular they

The “I just don’t understand…” crowd. I have yet to meet anyone who legitimately did not understand why a person would want to be called their preferred name, or why someone would want to marry who they love. It seems to just be a way to feel out if the person they’re talking to is amenable to list to their “discomfort” with whichever group they are referring to.

My trick is to ask to play a few songs on their phone on YouTube. You can learn a TON by someone's homepage and recommended videos

A big one is avoidance and awkwardness. It can just be not being used to, or scared of saying the wrong things eg not understanding pronouns. However, it can be a sign that we're a pariah to them, or their silent v sign.

Laughing is another one. Laughing at the idea of gay sex, finding transphobic jokes hilarious and things like that are subtle signs. Why are LGBT a joke?

There's loads of things, but IME those are the biggest.