i can visualize what's happening in this poem, and the lines of "get it down boy" and "get it down girl" create a definite voice for your poem. i'm not sure, though, that those lines work well with your rhyme scheme. those lines communicate franticity, and the rhyme scheme is a bit more relaxed than the lines i just mentioned. and, while either sets a mood that is good for your subject matter, i don't think both work together.
i really like the way the line "a long term lone of [sic] you spare kidney" echoes the line "dont think im gonna be an organ donator", but i'm not sure why you've placed emphasis on one refusing to donate an organ but requesting a donation from another (it seems that the narrator is requesting commitment from his/her lover without offering any in return). and i realize (at least i think i do) that this relates to the line "i cant stand up i dont understand why", but i'm not clear on what it means.
also, while i like the line "to see you smile i have to shut one eye", i'm not sure whether this is linked to drunkenness (16 cans of red stripe, especially at once, are really... uh... "effective"... you've communicated pretty definite inebriation, here) or to the attentiveness to organ donation (and/or this donation's possible connotation of commitment).
the rhyme scheme
of your first three lines don't really work with the repetition of the next two lines for me (the same goes for the repetition of this scheme), but the repetition of the lines "i can't stand up/shut one eye" work very well, in the same manner that the repetition of chorus lines work to create rhythm and cohesiveness in a song.
i think your poem would be much more effective if you focused very much on the ideas you want to communicate and paid attention to how your schemes of repetition worked together to communcate your main ideas. i think this poem's strongest attribute is its informal conversational tone.