Hot Sex

Doing the Hot Tub Etiquette path will get this one.

Hand Job

Slight variation of Hot Tub Etiquette
Start with Pizza Dinner or Steak Dinner this time:

Go to the bedroom to put on a swimsuit
Wait for her in the hallway
Get in the hot tub
Suggest playing “Truth or Dare”
Truth  or  Dare (does not matter)
Yes  or  No or Finish dare (does not matter)
(Pick a question, does not matter)
(wait for her to finish answering)
Dare
End dare
Dare her to take her top off
Dare
Dare her to get naked
Kiss her nipples
Massage her thigh
Rub her pussy

Wet Clothes

All you need is for Ariane to be dressed or shirtless with at least 3 drinks, then ask to go swimming. So you can do Steak Dinner

Go to the backyard
Have a drink
Go to the pool
Go Swimming

Backyard Play

Go swimming, challenge her to a race, look at the telescope and get in the hot tub on the same date. Doing the start of Thing to Do When Your Naked Part 2 and then after dinner getting into the hot tub, will earn it.

Hide And Seek

Doing the Pool Hijinx path will get this one.

Steal From Rebecca

Do the variant of The Rebecca Trilogy 1 – Marco Polo where instead of swimming you go inside for drinks.

Topless Picnic

This is covered in the Thing to Do When Your Naked Part 2 path

Wrong Breast

Do The Rebecca Trilogy 1 – Marco Polo but when its your turn:

follow the noise

and you will end up grabbing Rebecca’s breast.

You Got Mail

This one is covered in Truth or Dare path

Swim Champ

This one is covered in Pool Hijinx path. You must win a race.

Underwater Explorer

Get Ariane to skinny dip, then challenge her to a race.

Purposely take too long clicking A B C so that Ariane will finish ahead of you. You get a nice view from behind.

See Pool Hijinx for more info on how to do this.

Voyage To The Moon

Start with Start of a Romantic Evening

Dance
Keep dancing
Protect Ariane
Drive back to Ariane's
Go to the backyard
Check out the telescope
(get the answer right)

Ariane will now be naked, achievement unlocked regardless of whatever else happens.

Squeeze Play

The Thing To Do When You Are Naked path covers this one