Nope. They started having consensual sex after NK lost hope over his teacher and asked NK to 'hold him'. After that, NK behaved almost like a concubine where he would just wait for SH to come and fuck him almost every night. When SH got sick and they both reunited in the doctor office, NK was aware of SH's feelings and he started to question his own feelings as well. That night, right before the kidnapping, you can tell they had the most loving and sensual sex so far. But I guess it would be nothing comparing to what they are about to have in the coming chapter. NK is now convinced by SH's true feelings towards him so he will let go himself like he never did. The epitome of tenderness and sensuality would be something close to their very first night where NK thought he was making love with his teacher...
So... It's their first sex with consent right?