To sweat profusely. R.Kelly has an addiction to young girls, and if enticed by something such as a girl scout meeting he would try to resist his urges causeing him to sweat.
We were playin and mah man was Sweatin like R.Kelly in a girl scoutmeeting
12 step recovery jargon referring to someone new who talks about how great life is, now that they'resober. Usually meaning that the person is out of touch with reality.
The new guy seems pretty happy for a dude who has no job, no money and no family. He must be on a pink cloud.