Here is the full list of all 16 Pirates: Golden tits: Chapter 1 achievements.
Have a total of 10000 Escudo on yourself
Leave an uninhabited
Touch Jaina while she's asleep
Peek at the bathroom
Win an armwrestling tournament 5 times
Spend 20000 escudo
Finish 10 bounty hunting commissions
Activate a cheat mode
Catch 50 fish
Fully upgrade your ship
Spend 100 days sailing
Sink 10 ships
Journey Begins
Beat Saint-Isidor bandits 5 times
Visit a brothel 10 times
Listen to all of the Twig's poems