but this would definitely burn bridges.

I guess I should clarified that this is more of something you'd say in the beginning, not too long after meeting someone.

You're basically giving them them an ultimatum to date you or cut off contact.

I mean I see it more as you know who you are and are setting boundaries for yourself. If the other person insists on being friends while knowing that you are into them, I see that as kind of manipulative, because you're kind of pressuring the person with the feelings to make a decision to stay in an awkward situation.