Drinking Problems
One of my stated goals in making this new version was to avoid having to get Ariane drunk to do anything. I accomplished that goal, but the getting drunk scenarios are still there. You could feed her a lot of wine, but the easiest is at the bar downtown. Here are two such scenarios.
The first starts with Start of a Romantic Evening:
Bar One martini and one beer Order another round Wake her up Wait for her in the hallway
This is the classic drunk ending. To get to a more interesting ending Ariane needs to like you more, you can do that by playing trivia first. This time start with Steak Dinner:
Go for a drive Get in the drivers seat Go get some gas Fill up tank Go Downtown Nightclub Bar I’m driving, so club soda please Order another round Carry her to bed Tuck her in
Take her clothes off used to work in DA 7.2, but I got rid of it, if you do choose it, the ending picture is an interesting one shown above.
This is the only way you can actually sleep over without the sex, or without Rebecca, but that walkthrough is coming later.
Date Ariane Games 
It seems in Date Ariane HD version 2.0 “HD”, from September 9, 2018, build 200, there is now at least one other way to sleep over without having sex, and this is a new one. Sometimes when you and Ariane head for the bedroom, at the last minute she changes her mind and decides she is not comfortable with sex, and asks you to sleep on the couch. If you agree to this, you sleep on the couch, sleeping over in her bed without sex. If you don’t agree to sleep on the couch, she kicks you out of her house.
So now there are 3 ways to sleep over without sex: by getting Ariane drunk, by having Rebecca along and Ariane too tired to kick both of you out, and by having Ariane turn you down at the last minute after you take her into the bedroom so that Ariane asks you to sleep on the couch. I don’t yet have a set of reproducible steps to get Ariane to ask you to sleep on the couch, but this is an interesting new possible ending that makes the game more complicated and less predictable. I just happened upon this other ending randomly.