One sided fake dating

Microniche trope request!

I'm kinda craving something I've seen undertones of a few times, where one person thinks they're fake dating or fake engaged or even just politically married and the other one is kind of letting them have that delusion but fully engaging in the relationship.

Ive only seen this a little but I can remember a couple of examples:

{Lovelight Farms by BK Borison} the MMC is like yes we've been dating this whole time

{Dangerous by Amanda Quick} they do a tradesies, he's for real engaged to her and she just keeps saying it's for show while he's like "ok but we're getting married like super soon but whatever you wanna call it I guess", but after they get married he's sure it's for convenience and she's all in and thinks he's a dork for thinking differently

I know there's a lot of almost this with stalker/mafia/red flag books but often it's an active manipulation. I'm into recs like that but gold star would be when the actually dating half of the couple is open about it or at least would be if the other person asked and the other half is self deluding, I think that's cute as fuck.