Nothing/no one can come between us.

As ever, context is everything. Some options:
Nothing can separate us.
Nothing can split us up.
Nothing can keep us apart.

oder wie Frankie Boy sagte:

(We) Go together like a horse and carriage :-)

no distance can keep us apart as long as you're here in my heart.
Two worlds collided and they could never tear us apart
wild horses couldn't drag me away!
Let's, let's stay together, Lovin' you
whether, whether times are good or bad, happy or sad

I-ee-I will always love youu-uuu-uu-u-uuu-uu!


sorry, I got carried away...