Unreasonable? Nope. One thing I've learned with experience, you can turn down invitations without explanations, and that is just fine. If pressed, "I don't want to go" is explanation enough. People want to guilt you with family shit? Fuck 'em. The people who care don't matter, the people who matter don't care. May you find harmony. Good luck sweetie.

Imho, don't make up some excuse, just tell them 100% straight out the truth, you don't really need to associate with scum like that even IF he is a part of your family.
Try organising an event of your own and NOT sending that piece of shit an invitation plus instruct ALL other invitees that HE is 100% UNWELCOME to attend.

I wouldn't go and don't feel guilty. It's difficult to do but I have severed connections with several family members who have no respect. Life is too short and I am too old to give a fuck anymore.

Why even feel guilty about it? Your mom invited him. You don’t want to see him. You don’t go. You don’t worry about it. You tell them why. Easy peasy.

I’ll go with you, and be like your bodyguard. If he comes within 10 feet of you, I’ll say I’m sorry sir step back please.

You're not unreasonable. I would be honest and say that I have no desire to be around this person.

Wouldn't go. I wouldn't lie about why either.
Would definitely say it was because of him.

If it's clear to me that my feelings are not being respected, I don't put myself in situations where that shit is rubbed in my face.
I'm not going to worry about how that gets perceived by anyone.

You have every right not to be subjected to anyone.

I understand why you would want to stay away so you should trust your gut. He sounds like a very shitty person and it sucks that his presence would keep you from being with your family. In that regard, maybe put a laxative in his food or drink so he'll have be in the toilet the whole time.

I give terrible advice. Don't do that.

If he's still dealing , make an anonymous call to the police on him . That way , he is removed from the family gathering , not you .

I would not go and I would tell my mother that I feel very uncomfortable around a man that sold drugs to my sister.

Try holding your own family get-together, inviting only he family members you want to attend.

Do what ever brings you peace. Will seeing him outweigh your pleasure at being with the rest of the family?

I think I'd talk to my family about how uncomfortable making this is.

Perhaps they're in the forgiveness business and maybe he's trying to turn over a new leaf - but he's been a creep in your life (and your sister's) so far and they should acknowledge that.

You need to know if there is any attempt at change on his part - or if they're keeping him around to see if he can repeat the same crap again. (Which just wouldn't be wise now would it).

It's okay to state an opinion with family even if it differs from their own.

Would you drink water laced with lead? Would you take toxin? This guy is clearly toxic, and it sounds like you're doing right by yourself staying away from him.

Nah. Use the oppourtunity to confront him about his drug dealing, that he ruins life, that he should apologize to your sister and try to make amends for what he did.

The flat earth stuff doesn't matter. He isnt deciding textbooks or government policy. If he starts on it tell him to STFU.

Other than that just make his stay very unpleasant...in your face, everybody can seeb unpleasant. I have no sympathy for drug dealers. F***k 'em.

No, you sound very reasonable not wanting to be around this guy. You can choose not go attend and be honest about why. Tell anyone who wants to know why you refuse to attend and let those you will miss seeing that you look forward to doing something with them without their uncle the pusher. You can't control who others choose to be around, but you have every right not to attend functions this guy is invited to.

You take your fist and when he is sitting down and you are in a standing up position as hard as you can turn around clock him on the nose with your closed fist. Just make sure you hit his nose dead on. This has no weapons or DNA involved but the witnesses may be a problem so secure a good location.

(The following is a joke.) Maybe find out which flavor of Flat Earther he is, and then randomly float a competing Flat Earth theory. I hear there are several factions of Flat Earthers now who really hate each other.

I would not go. But do what you feel is best for YOU.

Nope

I’m sorry but your sister and mother have a very bad memory

If he pimped your sister.... why haven't you told the Police?

I have ditched half my family over their overly religious opinions and support of trump. I completely understand your choices here. I have no other advice, but stay strong and keep your standards high

I know how hard it is to have to avoid certain family members. But, I would not go where I would be that uncomfortable...if another person that I do not trust is invited. Let your mom’s guest enjoy themselves, and visit with them on some later date when the ‘half uncle’ is absent. It hurts to take ourselves out of family gatherings, because we want to belong to our family unit. But, making ourselves sick will not help us or them. When, you can go to these gatherings and not feel emotionally distressed, then it would be ok, but until then you have a choice to make.