What if your DP and PIL had to move in together without you and DH there? Would they get on or would they drive each other bananas?
I think my DPs' love of watching a lot of telly would rub up pretty fast against my PILs' crazily busy social life, as would MIL's very early rising.
(We've been watching new Marvellous Mrs Maisel in which - very tiny spoiler alert - her DP and PIL spend sometime in the same house and it does not go well)