Horn-dog(Slinger)

Achievement Unlocked: Horn-dog Raise your Libido to 25 or higher through stat points, achievements, or otherwise!
 * 50% of your Libido is now added to that of your consenting partner(s) during sex!
 * Your sexual fluids no longer taste disgusting! You’re welcome.
 * (Some) Libido Perks Unlocked

Reference
Unlocked in Chapter 24 "Loot Galore"