standoffishly, he declined the invitation to the office party.    From Wordnet, Princeton University. 

His girlfriend, Becky, the hottest girl in school, stands next to him, standoffishly.    From Wordnik.com.  [CollegeHumor: Recent Articles] Reference

Party honchos have standoffishly avoided endorsing even the simplest elements of the plan.    From Wordnik.com.  [The Full Feed from HuffingtonPost.com] Reference

Four or five tables, cases and stands, backed standoffishly against the tapestry on the walls, and the legs and bases of this furniture were great -- unbelievably great, rococo gilded legs -- legs that writhed and twisted themselves in a sheening agony of impossible forms, before they resigned themselves to dropping to the floor in distress.    From Wordnik.com.  [The Martial Adventures of Henry and Me] Reference