Backyard Picnic
This is the last of the dinner walkthroughs, it is not ideal but leaves her in a swimsuit on the patio with many options to choose from. This is updated to work with HD version.
Give her a hug Read her a poem There's something about a Martini, Move in closer* Kiss her Run fingers through her hair Go somewhere else* Turn on some music Pick a Rock playlist Change music Pick a light Jazz playlist Go somewhere else Let’s go to the backyard Change into a swimsuit Wait in the hallway Swim some more Lets get out of the pool Have a barbecue steak dinner Wait for steaks Talk to her Are you into sports? What sports do you like to do? Drink Wine Give her a compliment You are so pretty... Eat steak
There are two pre-dinner activities you can do which have not been explored yet as they are also post dinner activities, and will take away trait points if you fail: Challenge her to a race in the pool, and Check out the telescope.
The rest of these walkthroughs will start where one of these 5 dinner walkthroughs end. It is highly recommended to save your game at this point.
*if you do not see this step skip it.
Date Ariane Games 
How do you get to the nude backyard picnic scenario?
There isn’t a way, but there’s a chance there’s pictures for such a scenario.
Will that scenario possibly be added in a future release?
It seems that in the Remastered version, Ariane will *not* go swimming without eating first & this interferes with the flow of this scenario and a couple of others.
In the Remastered version, it seems to be next to impossible to follow steps like those above and get Ariane to change & got swimming / get in the hot tub *before* eating the steak dinner.
You’re right that old walkthrough wont work for Remastered.
This one will https://arianeb.com/backyard-picnic-1/
Full walkthroughs for Remastered can be found https://arianeb.com/da-remastered-paths/
Or within the game itself in the Help section.