Aynone else a bit disturbed by the kissing scene?

No problem with the kissing scene. The actress and her character were about 18, the actor and his character were 25.

When it comes time for the end of the world, you can afford to drop your "partners' age must be within three years of my own" rules.

Far more disturbing to me was training children to be cannon fodder.

WARNING!
Objects under T-shirt are larger than they appear!
👅

When the apocalypse comes, social conventions are some of the first things to go. In the pre-industrial world, a 30 year old man and a 16 year old woman would not be unusual at all.

Also, pedophilia describes sex with prepubescent children, so that word does not apply here, as much as people like to throw it around.

... and in two years time (or whenever she officially turns 18 in the film), it becomes a non-issue.

Reality check needed.