Revealing one's TG side is a disturbance to a relationship.
All relationships have a differing level of stability, ranging from "Weebles wobble but they don't fall down" all the way to a pencil standing on its point.
The question is, will the disturbance be enough to topple the relationship? Plenty of relationships topple without CDing even entering into it. Others are already teetering on the thin edge and the slightest push is all it takes. Many experience some bumps, but the relationship stands fast.
The main criteria seems to be how good a relationship has been built before the "reveal." How many trials has it withstood? How committed are the partners to each other?