I told my boyfriend on our first real date. However, later into the relationship, he did try to blackmail me with it (during a heated argument), by threatening to out me to his family (who I never wanted to know, since I never trusted them much). So in partly revenge, and partly just not wanting another person to have any power over me, I told them all myself, just to spite him. Much to his frustration. Oh well, let me cry a river (that last part was sarcasm, he got what he deserved in that instance).
Long story short we are still together and love each other though. It's a very complicated issue, and it can be difficult to navigate. It's good that you are being thoughtful about it.
My boyfriend before him is a very liberal person but had a huge problem with me doing sex work, and would never get back together with me, since I made the choice to be a sex worker. That hurts, but it's his freedom to see the world the way he wants, and at least we can still be close friends, and exchange platonic caring.