Lars and the Real Girl (2007)
106 min, dir. Craig Gillespie
Extremely shy, anxious Lars surprises his brother and sister-in-law with news of Bianca, his new girlfriend... only for them to find out it's a blow-up doll. On the town doctor's advice, they – and the rest of the town – decide to go along with the delusion.
The doctor states up front that Bianca is a crutch, a sort of displacement for his anxiety around his sister in law's pregnancy. Not only are his family and the wider town explicitly supportive of Lars, they actively do things to make Bianca 'involved'.
For something released in 2007, I wasn't expecting this to as affirming as it was.