"seeing her face by the light of a post-coital Craven A".

I could never understand how smoking in the dark could be enjoyable. The only reason I ever smoked was that the Army allowed a break every fifteen minutes for a cigarette, but non-smokers were supposed to keep on working.
But there was a certain fascination to watching the vagaries of the plumes of smoke. The mere nicotine effect of smoking in the dark never appealed to me.

The bombshelter bit reminds me of a joke in Time magazine during WWII.In the dark,a girl gets kissed by a stranger. When her boyfriend discovers this he blusters: "I'll teach him a thing or two if I catch him!" The girl replies dreamily: "Oh, Albert, you couldn't teach him a thing!"