I'm really stunned that any intelligent woman would advise Leigh to keep quiet about all of this. It's terrible.
If i was to become a step-parent, that's a choice i should make by myself, not have my partner force it on me.
If i had to spend 18+ years making sacrifices, providing for and forming a bond with a child, I would deserve to know all the facts first.
If my partner had cheated on me, and continued to have sex with me (potentially giving me a life-limiting disease), i'd deserve to know asap in order to get myself checked out.
I'd deserve to know that i had been cheated on. I'd deserve to make my own mind up whether i wanted to spend any more of my life with someone who had betrayed me.
Like someone else said upthread, would you be happy for your husband/partner to go and have a one night stand with someone and father a child behind your back?
That poor man. He is about to become a parent. He is about to sacrifice so much to bring this child up, being led to believe it is his son/daughter.
I agree with what several others have said. The truth will come out later if not now. And that poor man's life - and the child's - will be shattered. Imagine forming such a close bond with a child you think is yours, only to find out you're not in any way related to it.
Leigh, you have to just suck it up and be brave. How can you genuinely be happy with the rest of your life with this massive bombshell niggling at you, waiting to be dropped at any second?
What happens if you give birth and the child has some sort of disease/disability? Doctors will want to know the maternal/paternal family medical history.