For the last 4 months DP and I have shared DS care. We are both working part time. DS, I think is attached to both of us but enjoys rough play with my DP. In the last few weeks he has cried when either one of us has left for work and needs a bit of distraction or cuddles at that time. Now he has begun crying when DP leaves the room not all of the time but often enough (and it's not even when they have just been playing). DP says it is a tantrum and shouldn't be responded to because it's a tantrum. If I'm on to it quick enough I use distraction, but it's hard to get onto it always as people are always in and out of the room.

DS is 10 months old. Could this be a tantrum? I thought tantrums happened when they are older. How would you deal with crying when a parent leaves the room?