My g/f did this to me while watching a movie in a theatre and holy crap did it feel great. It was ticklish and sensual at the same time.

Basically she was kissing my neck slowly, and would breathe in and out
slowly, as well as just caressing my neck with her lips.

It felt like that side of my body was like getting paralyzed and it was awesome.

I once tried to do it on my g/f didnt realize she had just got off from work so
it was kinda nasty/sweaty tasting.

With good cologne/perfume it makes it hella better (just make sure the neck is clean).