I think I would change it up a bit:

how do we go
from daily liking
each others' instagram
to casual sex

Since "how do we go" and "daily liking" sound cute and almost fairy-tale-like, which is then modernized by "instagram" and brought home by "casual sex" / impending penetration and fluid exchange. I feel like there could be a line after "instagram" that adds to the buildup, something like "to what we want:" and take out the "to" so it reads: "how do we go / from daily liking / each others' instagram / to what we want: / casual sex."

/ramble

EDIT: I guess the "what we want" implies mutual attraction; you could always make it "I" or just ignore me altogether.

There are advantages and disadvantages to "I" and "we". "I" is obviously more personal and shows the creator is the subject but you also allow the reader, when reading aloud, to put themselves into that position. With "we" you can refer to the two people who are involved in the action but also we in a more general sense of people and interactions and some greater sense of interactions based on technology. Something like that.

I took out "photos" because it's extraneous information -- the only thing to like on instagram is photos.

The thing with natural line breaks is that, in lines so short, they look arbitrary, not natural. So what you gain by controlling them, I feel, is more than what you gain by making them look like prose. I'm not saying you're wrong--I think the original is perfect as is--just saying this is how I'd handle it. I also come from a more narrative school that often relegates turns/epiphanies to the end of the poem, which has the unfortunate side effect of occasionally Billy Collinsing the **** out of lyrical work.

I'm good at poetry
it's basically symmetry
with words
and swords