Wedding invite?

Me and DF are getting married end of October, very small wedding, immediate family only and 2 of our closest mutual friends. I can't decide whether to invite my dad's wife. She has been emotionally blackmailing me since I was 13/14, is the 'other woman' and her 2 children are possibly my siblings, but my dad won't give me any answers. I really don't want her at the wedding, because I don't like her and see no reason why she should be there as I don't count her as my family, but my dad does. I'm worried that if I don't invite her, that she'll start more smurf again and make the run up to the wedding awful and probably the actual day too. However, if she is there, I won't be happy with it.

I should add that yes my dad does know that she does this, and ignores it. My mum has given me any answers that I have asked for regarding their divorce and the reasons why, but she has always made it very clear to me that she is obviously biased and that until I get answers from my dad, I shouldn't accept her story as the true version. She is being more than fair. I also want her to give me away, as she has done so much more for me, DF and DS than my dad has, but don't know how to tell my dad this. Her suggestion was to ask my brother instead which could avoid the issue.

So, to invite or not? Completely at a loss here, as is DF, and my dad has a bad habit of being completely unreasonable. Help please!

It's your day. If you don't like her and don't want her there, don't invite her. Your dad will just have to deal with it.

I think it is YOUR day and if you don't want someone there then they shouldn't be there, if your dad loves you he should respect you and be OK with the fact that you don't want her there.

I wouldn't personally.

There are a few people in my family that aren't coming, my own father among them. Weddings are about celebrating love with people who care about you. Why would you have people who don't care about you there? That's just stupid.

its YOUR day! dont let now one bring you down on it.... if u dont want her there then your dad will have to deal with it regardless.

So she's his family, so what? If you don't consider her YOUR family, then she's not, and you're under no obligation to invite her.
So she misses out. Oh well. Not your problem.

Thanks ladies. That's what I thought I was gonna do, just got to get myself prepared for the crap that is undoubtedly going to be coming my way