They also don’t kiss, but that would probably be a poor segue for Then to make.

Answering a question had in the last few comments: sarnothi saliva is a paralytic venom. Selkie’s skin contact smooches only gave a painful irritation because she (1) didn’t break the skin and (B) is still a kid, a juvenile. Her potency isn’t developed yet. A bite from an adult sarnothi would render the affected area or even the entire body immobile, on top of the burning irritant factor. Death by cessation of breathing or heart muscles is also a possibility with this.

Hence the forehead-touches as an affection display.

(one sarnothi can affect other sarnothi but they won’t affect themselves, which is why Carrie could do the hand-smooch earlier.)

Spin The Bottle and Die