My ex and I's song:
Maps - Yeah Yeah Yeahs

Still some what true as I never stop loving people once I start.

My current bf and I do not have an official song, but he linked these to me so I find them fitting:

I Do - Colbie Caillat
I Call It Love - Lionel Richie

I linked him this because Hall & Oates is smurfing awesome.

You Make My Dreams Come True - Hall & Oates