Longtime friends Jennifer Lopez and Dwayne Johnson spent their night getting sweaty together . . . in the gym. On Thursday night, Johnson took to Instagram to share a photo of the pair looking pretty serious after what we can only imagine was a pretty intense workout. From what we can tell, it looks like the two were working out at trainer Gunnar Peterson’s exclusive Beverly Hills gym, a favorite spot of Lopez’s, who is a longtime client there. Peterson is the man behind many Hollywood bods, including Sofía Vergara, Minka Kelly, and the Kardashians.