S.B.
The testicles are mobile inside the scrotal sac, so maybe they both were over to one side when you noticed the empty skin. He was in the bath, so maybe he got cold and they moved around a bit. The other day I was changing my son's diaper and I freaked out because it looked like they weren't there at all, and I couldn't feel anything in there, but he was just cold and when he was relaxed in the warm bath later on all was where it should be. So I guess my point is to check again and see if it's still like that, and if maybe they are both over to one side. Also, ask him if he's hurt himself recently (sports, kicked, fell on something, etc.) and if he has any discomfort. You could then call your pedi's office and speak to the nurse to see if this is suspicious and warrants an appointment. The more information you give the nurse the better they'll be able to address your concern. Hope all is well!