[Fizzyology]

Hm a tough situation indeed.

It sounds like even though your Surrogate Mother knows your situation with your biological parents, she wants to try and help you and your parents to get to talk to each other and try to understand each other.

Since you said you don't feel ready to face them, perhaps you should try to talk to your Surrogate Mother about it. Tell her you really don't feel ready to talk to them, and that you want to continue the tradition of carving their pumpkins but you don't know if you'll be able to be yourself if your Bio Parents are there. I'm sure she'd understand, and even if she insists that your Bio parents are there, perhaps you should bite the bullet and try to talk to them, or at the very least, ignore them and socialize with your Surrogate Parents.

I can't say I know how awkward your situation is, since I pretty much am a shadow to my parents (they don't try to know me anymore and generally leave me alone) but I hope that this helps in some way.

Whatever your decision, I hope you the best :3