Am I wrong to tell my friend that is weird she is dating someone 20 years her senior?
Do you feel weird about it because of her or because of him?
Both. I don't trust her because she's so stupid.
I also do not think that relationships with a huge age gap is very appropriate, but as long as they are consenting adults and no one is harmed in the process I think we do not have any say about your friend's relationship. I would recommend that you would tell her that if she needed any help or if she needed any suggestions from you then that is when you can give them your support.
What, you are not even going to criticize her for it? Fuck you for not showing any major anger about this.
It's not your place to be angry about another person's relationship if both people are consenting adults. Regardless of how you feel, you have to remember your friend is allowed to live the life that makes her happy.