I've read a few threads on this in the last few weeks, and I can't honestly get over some of the responses.
Step mums (and potentially dads but it's usually step mums who write the op) are always wrong according to at least half (probably more) of mumsnet.
You see your stepchild often - you are too involved and should let the, have dad - child time on their own.
You don't see your stepchild often - you are not interested and your stepchild will know you don't like them
You have your own child from a previous relationship - focus on them and leave dad and stepchild to it
You don't have your own child - well you obviously know nothing about parenting
You have a baby with a man that has children already - you've ruined his current children's lives
You speak to the ex - you are too involved and over step the line
You don't speak to the ex - you should communicate better
You help your dp/dh with childcare - no you are too involved your significant other should give up work immediately and spend all his time with his child and not you
You don't help - you don't like your stepchild, you are selfish, you should act like part of the family
You have a good relationship with your stepchild - you have overstepped the line you are not their mum or their friend
You are not overly fond of your step child - you are pure evil and that's that
Oh and last but not least...... You knew what you were getting yourself into
Oh and let's not even get into maintenance, or the fact that obviously ex's are never wrong, never abusive, never threatening and always perfect mums who only want the best for their kids.
Rant over
And before you say it I know all step mums are not great and not all mums are shits I'm just saying mumsnet seems to think all mums are great and all step mums are shits