Authorities were called to Collins Lane Dog Park in Maple Shade Township around 6:30 p.m. on Tuesday.
The suspect, identified as Brian J. Miller, is accused of lewd acts in front of two teenagers.
When the teens attempted to leave, Miller allegedly followed them.
"Uncertain as to their best course of action due to their proximity in the park, they returned to the gazebo area and the male subject started to pleasure himself again," police said in a news release.
Officers were later called and Miller was arrested at the scene.
A further investigation also revealed that Miller had been lingering in the area earlier in the day, engaging with at least one other juvenile and an adult female along Main Street.
Miller is charged with endangering the welfare of a child and lewdness.
Anyone with additional information on the case is asked to call the Maple Shade Police Department.