The Pairing by Casey McQuiston

Ex-lovers Theo Flowerday (nonbinary) and Kit, reunite on a European food-and-wine tour years after a painful breakup and compete in a hookup challenge while falling back in love.

This book contains; alcohol (extensive), alternate gender/sexual ideologies, anxiety, BDSM (adjacent elements), death/grief, deception, DEI content (themes), depression, derogatory terms, drugs, erotica (potentially), explicit sexual activities/nudity, explicit sexual dialogue, fetishes, gender dysphoria, gender neutral/nonbinary pronouns, kinks, patently offensive sexual content, pegging, pervasively vulgar content, profanity, prurient behaviors, sex toys, sexual nudity, smoking, toxic relationships, vaping, and voyeurism.