The pair were seen getting close to each other at a party on Saturday July 26, reported Aceshowbiz.
"They were so together," an eyewitness said of Somerhalder and the 'Twilight' actress. Another source said that the pair was not hiding affection for each other at all.
Rumours of Somerhalder, 35 and Reed, 26, have been doing the rounds since the day he was seen holding her protectively as they went shopping.
Somerhalder earlier dated his 'The Vampire Diaries' co-star Nina Dobrev.