Stellar and satellite configurations

When I get on top 
of you, you're 
the world and when 
you get on top of me, 
you are sun, or moon 
depending on cowgirl 
face or base. And when
...ahh,
I don't even know what 
that is. 
Just ace or service return, 
and if we can't tell which 
or who's up/down/back 
first? That's a tennis match, 
I guess. I know it's love, 
but by crook, snatch, catch 
I couldn't rule anything out 
of bounds now. Some referee 
I am, plowing downfield to
score, and 
how.