How does tom's presence affect the atmosphere of the party?

Tom's presence makes the party's atmosphere awkward.

Tom is a character in a novel gatsby, he is a solid, straw-haired man of thirty with a somewhat hard mouth and a supercilious way. Two sparkling, haughty eyes had set up strength over his face, and gave him the presence of continually inclining forcefully forward-you could see an incredible pack of muscle moving when his shoulder moved under his thin coat. 

Tom's presence makes the party feel awkward. This is because Gatsby wants Tom to leave her and come back to him as if there was nothing wrong in the last 5 years. But Gatsby failed because Nick told him that he cannot repeat what happened in the past.

In 911, a group of vikings lead by rollo besieged paris and chartres. after a victory near chartres on 26 august, charles decided to negotiate with rollo. the talks were led by hervé, the archbishop of reims. this resulted in the treaty of saint-clair-sur-epte, which granted rollo and his soldiers all the land between the river epte and the sea. it also granted him brittany, "for his livelihood". at the time, brittany was an independent land which france had not been able to conquer. in exchange, rollo promised the king his loyalty and military assistance when needed. also rollo also agreed to be baptised and to marry gisela, the king's daughter. the territory given rollo is about the same as upper normandy.