Eventist
One who will not attend informal social events and/or events that do not bare historic or cultural importance.
Percy is an eventist - he said he CAN now come to our party since i've told him that it's for our engagement
Or
Rowena declined to join our family trip to Milnthorpe until I told her it was an annual thing, she's an eventist.
Or
Rowena declined to join our family trip to Milnthorpe until I told her it was an annual thing, she's an eventist.