It's rude to exclude someone with social anxiety.
Sally is planning a party and deciding if she should invite Megan or not because Megan gets nervous in crowds.
Sally wants to throw a fun party.
Sally decides to invite Megan and stay by her side until Megan feels comfortable.
Sally decides that Megan would ruin her party and doesn't invite her.
Megan feels comfortable enough to come out of her shell and tell jokes and makes everyone laugh.
Megan finds out she isn't invited to Sally's party and tells their friends who decide not to attend the party either.