What did Alex mean by "Rolling In The Park"

Ok, maybe I'm a little naive. But in the episode "Summer of 82" Alex loses his virginity to Stephanie the girl who he delivered groceries to. Afterwards his ego soars, and his attitude changes. He claims he is ready either marriage, or a full time commitment with Stephanie. He says he gong to "Rolling In The Park". Elyse acts if he is going with Stephanie, and Alex says that he first gong alone to practice. Then later he when he goes to Stephanie's apartment he is shocked to see Stephanie with Pete. Alex is devastated, when Stephanie says that she doesn't want to get tied down to one guy. Before Alex leaves, he motions to Stephanie that he had plans for them to go "Rolling In The Park" and that he had been practicing So my question is what did he mean when he said "Rolling In The Park.