Reed, 26, looked fit in black and green leggings and a black tank top. The Vampire Diaries star, meanwhile, donned a long-sleeve black shirt and casual gray shorts.
Us Weekly broke news last month that Reed and Somerhalder were more than just friends, and they haven't been shy about their relationship status since. Some of their low-key dates so far have included dinner in the San Fernando Valley and at Kiwami in Studio City, L.A. Earlier this week, Somerhalder revealed they even adopted a horse together.
"Proud new dad," the CW star, 35, tweeted. "What amazing creatures they are. Wow. His name is Eagle. Thank you @iamnikkireed for snapping this special moment, with our big baby boy."
Somerhalder's ex Nina Dobrev, meanwhile, seems to be focusing on her own love life these days. (The Vampire Diaries costars split in 2013 after three years of dating.) The 25-year-old—who, like Reed, has previously dated Dancing With the Stars pro Derek Hough—joked that she needed a "steady boyfriend" during The Tonight Show With Jimmy Fallon on Aug. 5.