My grandpa passed away last summer from a battle with cancer and it's been super hard on all of us. We only found out in May and were told we would at least have one last holiday season with him, only to lose him in July. Around 6 months after he passed, my grandma made an online dating profile and started exclusively dating someone almost immediately. We were all cool with her deciding she wanted some companionship because she's a very social person, but no one expected her to move on so quickly with this man and take their relationship as far as it's gone in less than a year. Frankly, none of us like him and she becomes a completely different person around him. She no longer acts like the grandma I've had for the last 26 years. He acts as though he's above us because he has more money than any of the people in my family do, and hasn't even attempted to try and give us a good impression of himself. It's like he doesn't care what we think of him because he figures he's not going anywhere so he's honestly just rude and miserable to be around. He literally went through my parent's mail at their house on my mom's birthday (when he wasn't even invited) and started accusing my mom of doing shady stuff like stealing from my grandma because my grandma's name was also on an envelope regarding a bill in her name that my mom took over paying. And he didn't even apologize once he learned he was in the wrong. He just rolled his eyes.
Because they've gotten very close very quickly, I'm already worried about having to invite him to our wedding. I am the first grandchild to get married and while my fiancé was able to get to know my grandpa very well and have a great relationship with him I never imagined that I wouldn't have him around for my wedding and I'm devastated. Having my grandma's boyfriend there is going to just remind me that my grandpa isn't there and will honestly really affect my emotions on our day. I know it's rude to not invite him, so I do plan to, but how far do I need to go to make him feel included, when I do not want him included at all? I do not want him in our processional with the other grandparents nor do I want him sitting with my family during the ceremony, he doesn't deserve that role and I don't want to look at them and see him. I also don't want him in any of our professional photos, especially not our family photos. With how my grandma has been acting (telling us he loves us too and trying to act as though we're all family with him) I can see her being offended that I refuse to have professional photos with him and of him. I'm cool with like one or two phone photos, but I don't want the photos I'm paying for to be with some man I don't like or respect because he's given none of us respect in return.
Does anyone have any advice? I understand that I'm coming across as super cold, but there is literally one person in our entire family who likes him, and that's my aunt's husband who is a terrible person and none of us really like anyway, so he's obviously in good company. I know I should invite him, because "If I'm asking them to honor my relationship I have to honor theirs" but I don't care to honor him in any way. shape, or form and if I was assured that my grandma wouldn't be upset I would never invite him. But I also don't want to hurt her.