I would never say "we were best friends, but didn't swing from the chandeliers." It's a very odd to use that idiom. "Swing from the chandeliers" is a way to describe the activities wild party where people do crazy, silly things and have a fun time. Instead of saying literally what you did (or are planning to do), you can just substitute that phrase and people understand that it was fun and out of control. example: I'm can't wait to go to Jeff's party tonight, we're going to swing from the chandeliers. or "Are you already at the party? Is it fun?" "Yes, I'm here. No one is swinging from the chandeliers, but it's still pretty nice." I would never use the phrase to describe a relationship- only an event, and I would be unlikely to use it for anything that wasn't a party.

Thank you for the comments. I was wondering this is a fixed saying or something. (by the way this is a quotation which is way older than the song.)

Hello PercheNo, ‘To swing from chandeliers’ is a metaphor that simply means to have a ‘wild party’ or ‘partying to excess’ –Sia’s signing about it in her Chandelier song ‘ […] I’m gonna swing from the chandelier, from the chandelier […]’. In the context of your sentence, it means that your relationship was good but it wasn’t something ‘wow’ (thrilling or ‘wild’)

To ‘swing from the chandeliers’ is something you might do at a wild party with your best friends. If you ‘didn’t swing from the chandeliers’ then you had a good time but it wasn’t wild - so your relationship is good but not amazing.