go light on (someone)
To treat someone delicately, gently, or leniently; to not criticize, punish, or berate someone too harshly. Ah, go light on Bill, it's only his first day in the office.
go light on (something)
To use something sparingly; to use less of something than normal. I hope this horror movie goes light on the gore. I'll have the salad, but please go light on the dressing.
go light on
1. To use, acquire, or consume in small or moderate amounts: go light on the garlic.
2. To treat leniently.