i need advice.

You are not an asshole! This is really up to. Is she close with either of your parents? If you’re not worries about those relationships then I’d probably just not respond and let her get the hint. If other members of your family are going to be bothered by her asking them, it could be best to be direct and let her know you kept the guest size small and had to make the difficult decision not to invite her.

NO YOURE NOT AN ASSHOLE!!!! This is YOUR wedding day and you need to be surrounded by the people YOU BOTH LOVE and care for. I would just ignore her like your FH said. She’ll take the hit. If she wants to start drama about it on her own time that’s on her but just ignore it all and stick to your guest list. Put your foot down and whatever you do.... DO NOT GIVE IN AND DO NOT INVITE HER.

Ignore her and tell those invited who are close to her to ignore her outbursts.

View Quoted Comment Its my Dad's sister and they have a complicated relationship. And he asked me to invite her even went as far as to offer to pay for her. I explained how I felt and he respected my view and hasn't said anything since. I think I'm just more or less worried that she will find out and convince my family that I did invite not to come. (She's done things like that before) I'm so worried its gonna blow up in my face.

This may sound harsh but if she convinces other family members not to come, then that’s on them. Stand your ground and enjoy your wedding with the people that love and care for you. Weddings are stressful in itself (and exciting and amazing!), you don’t want to worry about family drama.

Just ignore her. And anyone who asks. She knows good and well why she’s not invited.
And give yourself the gift of freedom from jerks. You don’t have any reason to talk to or interact with her ever again.

If you don’t want her there and feel strongly about it, you absolutely shouldn’t have her. It sounds like you should answer her next time she asks about it and let her know, otherwise she’ll just keep asking others and potentially show up uninvited.

If I were in your situation, I would just handle it directly. I would much rather have an uncomfortable 2 minute conversation than continue to have her reaching out to you and possibly other family members for weeks or months to come. If she was brazen enough to reach out to you directly to inquire about her invite, I’m sure she won’t hesitate to reach out to other family members (like your father). I just wouldn’t want to put them in that awkward position of having to deal with her or tell her she’s not invited. You made the decision not to invite her (and it definitely sounds like the right decision!), and now I think it’s your responsibility to also handle the fall out from her because of that decision. Based on the toxic relationship, I don’t feel you owe her a phone conversation if you don’t want to have one. A short, to the point text message would suffice. Nearly always, handling a situation head on leads to much less stress and drama in the long run. No use feeling anxious about it for longer than you have to (wondering if/when she will ask again, whether she will start harassing other family members, putting them in an awkward position, or whether she will just find out when/where the wedding is from other family members and just show up uninvited!) Ultimately though, it is up to you how you want to handle it.

I've been in this situation before. Mine turned around, but I can tell you about what I did in this particular situation. So my grandmother and I have a very rocky relationship, she acts up at nearly every family function we've ever had...at my 30th birthday party, she felt the need to announce that it was also my mother's birthday and nobody should be leaving her out, at Thanksgiving she lied and said she had pneumonia while she was around my entire family, including my aunt who was battling stage IV cancer. Anyways, she and I had a falling out because of all of these instances. And I didn't have her on my guest list for a while. I sat her down and was just blunt. I said she causes issues at everything, I don't want issues at my wedding, and she needed to make a change to come. Of course she was upset by all of this, but I told her that my mind wouldn't change until I saw some improvements in her behavior and if she really wanted to go, she would start acting like a civilized human being and stop causing so much drama for everyone else. And it actually worked, she has stopped and the last few family gatherings we were able to have were more pleasant. So if this is an option for you, I would recommend being honest as to what is going on. You can ignore her as well, but just remember that she's part of your family, so someone is bound to tell her the details and she may just show up in that case.

Write her a very brief and formal letter to tell her you are both restricting the number of extended family. Since you and she have not had a warm and close relationship since you have been an adult, you will not be issuing a wedding invitation to her. Tell her you hope to see her at larger family gatherings ( if this is so) or at the holidays.
Don't just leave her hanging.