The arguments are always 'oh Vaporeon is the best pokemon to fuck' but I disagree. Sylveon is the best pokemon to fuck. To start, a Sylveon's ribbons are actually a version of skin. They have muscles and can move around at will. This is amazing for cuddling, foreplay, and even fucking. Sylveon also has a great moveset for breeding. Sylveon can use baby doll eyes to make her look cuter and you more aroused. Sylveon also has access to Swift, Psych Up, Attract, Charm, and other moves to make the bedroom better. But the best of all? Sylveon gets a stab-bonus on Play Rough and Draining Kiss. The only way to get a Sylveon is leveling an Eevee up with high affection, so a Sylveon will be already close to the trainer, making training easier. I rest my case.