Well, I didn't know about that detail of your situation, it seens sticky. As Jamie said, if you are stealth and want it to keep that way for now, you will have to avoid the person.
However, avoiding human contact because you are trans seens cruel. It is something you would have to decide for yourself and no one can tell you what to do. If you decide to go on with it, I would disclose after a few dates, so that person has a general idea about you and the trans label doesn't shadows your personality, but not late enough so they'd find through other means, and certainly before going to bed with them, no matter if you are pre or post op.
Though if you are passing 100% you could tell them much later. I guess I don't know really what to say, so I'm stopping 😛