If you wanna be my lover, you gotta get with my Friends!

Jennifer Aniston and fiancé Justin Theroux stepped out for a cozy dinner with Courteney Cox at the Sunset Tower Hotel's Tower Bar on Monday.

"Jennifer looked adorable!" an onlooker tells PEOPLE. "She looked so pulled together and very chic. She was dressed casually, but in heels."

Aniston recently returned to L.A. during a break from filming We're the Millers in North Carolina with Jason Sudeikis.

"They were very calm and carrying on a regular dinner conversation," the source adds. "Jennifer had a big smile on her face. She and Justin both looked very happy."

It was the first time Aniston and Theroux have been seen out together since their Aug. 12 engagement.

The Sunset Tower holds fond memories for the couple. It's where Aniston and Theroux were first spotted out together publicly when they shared a three-hour casual dinner back in May 2011.

After dinner, the trio greeted designer Tom Ford, seated at a nearby table with Tom Hanks and Rita Wilson – who double dated with Aniston and Theroux last April – and several others. Ford was celebrating his 51st birthday.
– Paul Chi

Talk about a special guest!

Lady Gaga schmoozed with her boyfriend Taylor Kinney's family over the weekend, when she joined him at L.A.'s Westlake Village Inn for his brother's wedding.

Spotted by a onlooker at Bogies, the hotel's on-property lakeside bar and lounge, Gaga sipped on pineapple, orange juice and vodka.

Adds the insider to PEOPLE, "She was relaxing in a cabana with the wedding party."
– Jennifer Garcia

Jennifer Aniston and Justin Theroux headed to a favorite haunt, L.A.'s Sunset Tower Hotel, for an early evening dinner just before 7. The two arrived in matching leather jackets and settled in for their meal together. "They looked really happy," an onlooker tells us. "They were so cute, and when they were walking out he put his arm around her."

Sacha Baron Cohen and wife Isla Fisher were spotted dining together at Tower Bar inside L.A.'s Sunset Tower Hotel. The couple shared sea bass – but took a break from their meal to venture across the dining room to greet a friend: Johnny Depp's longtime love, Vanessa Paradis, who was dining with an older woman. – Michele Stueven

Jennifer Aniston returned once again to one of her favorite hangs, L.A.'s Sunset Tower Hotel, but this time the actress was there for a party hosted by pal Tobey Maguire. Aniston arrived early for the bash and joined two girlfriends in the restaurant for some wine, which they enjoyed along with a crudité platter at their window table. At one point, David Spade came over to say hello, but otherwise the ladies kept to themselves. After Aniston left the dining room, Molly Sims snagged her table for dinner with two friends. Later in the night, Courteney Cox and a glowing Isla Fisher dropped by Maguire's dimly-lit cocktail party.

Jennifer Aniston hit up one of her favorite haunts, the Sunset Tower Hotel's Tower Bar for a mostly ladies' night. The actress sat down for dinner and drinks with four girlfriends and one male pal. "She looked great, really happy and mellow," an onlooker tells us. "They all spent the night laughing, sipping wine and just having a really chill evening."