The only time I feel alright is by your side

This is not as sweet as some of the other songs here, but still it seems to express the feeling of "foreverness" and nesting, and the exclusion of the rest of the world.

The Kinks, from 1964:

I'm not content to be with you in the daytime
Girl I want to be with you all of the time
The only time I feel alright is by your side
Girl I want to be with you all of the time
All day and all of the night

I believe that you and me last forever
Oh yeah, all day and night I'm yours, leave me never
The only time I feel alright is by your side
Girl I want to be with you all of the time
All day and all of the night