Can't deal with thought of being a stepmother!

[user1480775842]

Please help, I have been with my fiancé for three years and we have a 4 month old baby.
He has another child with another woman after a one night stand, he only found out about the child when he was born and has tried on a numerous of occasion to be there for him but the mother messed it up every time.
They then suggested that he wasn't his so they had no communication for a few years, everytime he tried to do a DNA test she would cancel it etc.
Safe to say that she is hunhinged!
The list of how she has messed with my fiancée head goes on.
She has even contacted me and been rude to me saying that my fiancé was trying it on with her when I know full well he wasn't because he won't be in the same room as her unless there is someone else present.
Anyway i digress...
she has got back in contact and after both his father and my own trying to talk to her and come to arrangement to visit the child as he will not see the child with the mother present, he is now going to see the child at her mothers house.
Everytime they try to have contact it fails the mother messes it up and then there is no contact for years.
The child is nearly 5 and has met his dad 3 times.
I am struggling with the idea of being a stepmother and am afraid that I would be relieved if it went wrong again as if it does then my fiancé says he will give up until the child can come and find him himself.
It has caused SOO many issues between the two of us and everytime the child is mentioned I seem to lose my mind and he can sense it.
I am not sure if I can handle the situation any more and apparently the child is a complete and utter handful (not surprised by the sounds of how the mother is) I am very cautious of having my child around this little boy.
I am worried that my fiancé will want to spend more time with his first born than with us.
I'm not sure if I can handle it... please help!!!

It also doesn't cost much to go to court, better that than her continue to extort money out of you

Does he have an anger issue? Why should he be taking it all out of you? The fact that you are closest to him is not an excuse. Maybe that's the problem with him dealing with his ex.

Not having money to go to court is certainly is an excuse. He decided he had enough money to support another child, so difficult to feel sorry for him on that front.

OP ignore some of the ignorant people on here.... unless someone has been through something similar it seems difficult for them to understand your side of things...

You are in a terrible situation as is your fiancé.... any mother who has behaved the way she has should have the child taken from her... she chose to bring a child into the world knowing it was from casual sex (poor child... how can she explain that one??) with a man she knew had no feelings for her and didn't want a child. I admire you fiancé for trying to step up to the mark as many men wouldn't given the situation, unfortunately as a human being there is only so much someone can take...

You will never be able to stop her (the mother) behaviour/actions but you can learn how to deal with them better and that will be easier if you speak with your fiancé and find a way to deal with her together.... please remember though that the child, like you and your fiancé are victims of this awful woman and maybe try to think of the poor child being brought up by a woman like that.... take her to court and fight for the child....

I'm a step-mum and luckily my step-sons Mum is a lovely person and great mother who (like my husband) always puts their sons needs first.... I know my step-son will always come first and I love my husband for that but I honestly don't know how I'd cope if his ex behaved the way the mother of the child does....

How the fuck is the man a victim? He chose to have sex. A child has resulted. Op is also not a victim. She had a child with this feckless man knowing there was anther child on the scene. She should have thought harder about whether she could cope with the situation before she brought another kid into this sorry fuck up.