J.K.
Aftershave can be really irritating. Best to put nothing on freshly shaved skin if you're sensitive.
Have him shave after showers when the hairs are soft. If he uses plastic disposable razors, use a new one each time. If he uses interchangeable blades, they can be used a few times if they are cleaned well and dried between uses. Don't keep razors/blades in the shower.