I clicked on this DD on impulse, because the title caught my eye. I really liked this poem.

The first stanza is great. I love the succession of hyphenated phrases ("hundred-and-ten", "three-months", "big-haul", "never-dull", "wedding-gift"). It really adds to the lack of punctuation and creates a feeling of hurriedness, like you don't have time to explain but you put in all these details in anyway, and it really drew me in. I also really liked the way you used line breaks, especially for "stared at the late season watermelon/we grabbed on an impulse". That later line surprised me, and at the same time it was a good way to change the focus from the heat, the season, and the watermelon, to the "we" and their interaction.

After that, though, the second stanza was a bit disappointing. I really like the first three lines of the stanza, but after that, the pace slows down. I thought the line "believing it during each bite" took away from the feeling of the previous line – no need to explain any further that eating the watermelon makes them feel refreshed! It's pretty obvious already. Then, the parenthesis was a bit annoying. Not only did it cut the flow, it didn't really add anything to the poem. I would use parenthesis in a poem like this to say something that's somewhat in juxtaposition with the current image/message, not just to add in detail. (Also, the word "new" already indicates that fact that they already had a paper towel roll, and who opens a new paper towel roll before they need it? the "(we had been out)" is slightly redundant.)
In general, this whole stanza could be be a lot tighter.

The last stanza was also great. To be honest, it took me a little while to get the ending joke (and I still think it's a pretty silly joke – although also very sweet) but even before I did, I love how you managed to line up the two lines so that the joke reads naturally from one to the other, and one has subconsciously already gotten the end of the joke before one reads the last line – and it just makes the whole thing so much more terribly sweet and cute (in a good way.)

Too answer your questions: It's not too long per say – I don't think there's such a thing as set length limit for poetry – but I do think there is stuff in there that you can cut, as mentioned earlier. It's not too prose-like – again, I'm not even sure there is such a thing – it's a very particular style that reads off the tongue and feels very honest and direct, and I think rhyme or alliteration would only take away from that. If you wanted to be more "poetic", adding more imagery could do the trick, but I think it's a great poem already.

Congrats on the DD, and I hope you find the critique useful. <img src="e.deviantart.net/emoticons/s/s…" width="15" height="15" alt="" title=" (Smile)"/>