Long, 35, and Seyfried, 27, dressed casually while running a few errands on Tuesday, Aug. 27. The smiling couple were both spotted holding smoothies when leaving a dog store and were later spotted relaxing at a Los Angeles park and hanging out with friends.
"They had a great foundation going in so it has been going very well, they've been spending a lot of time together," a source told Us Weekly. "Justin and Finn get along very well I hear, which is very important to Amanda of course. [Long's] a big dog person, I can attest to that."
Us first broke the news in late August that the couple were dating. "Justin is super private about his relationships, [so] I'm not positive how they exactly met, but they've known each other for awhile," another source added.
The two may be keeping their new relationship private, but Seyfried did take to social media to post a picture of her new beau. The Lovelace actress posted a funny picture of Long's head photoshopped to a llama on her Instagram account the very same day as their park outing.