Kylo Ren quietly threatens Rey with electric shock/force shock while she is restrained in his interrogation chair of terror. The idea fills her with both fear and a strange sense of excitement, Kylo Ren senses this, and draws out the experience. Tender kissing beforehand with a somewhat unwilling Rey and plenty of dubiously consensual cuddles afterwards to help the pain go away! This could be a Dark!Rey training to withstand torture situation or just a normal prisoner situation like in the movie.