It has recently occurred to me that there is one relationship within the Simpson family that, well, doesn't exist, and that's the one between Bart and Maggie. With this sole exception, every family members relation to very other member has been explored, and has a specific dynamic. In the case of Maggie, for instance:
Maggie x Homer = Homer often forgets Maggie even exists
Maggie x Marge = they have a very close bond and are usually seen together
Maggie x Lisa = Lisa often tries to teach Maggie about the world (granted, this has probably only been seen like four times throughout the series run, but it still counts)
Maggie x Bart though... well yeah, nada. I'm not saying that i have any suggestions at all as to what one could possibly make of it, but i still think it's a little bit strange that after 21 years, the writers have apparently never bothered with even attempting to do anything with the pairing (which is especially strange since several other relationships in the family has been absolutely milked to death, such as Homer x Lisa, Lisa x Bart, ect).
Oh, and please don't come with that "they have a buddly-like relationship" (as stated on Bart's Wikipedia article), because i sorely suspect that notion comes solely from the episode where Milhouse moves away and Bart therefore starts spending time with Maggie. And not only did that dynamic only show up once, but it was obviously presented as being out of the ordinary ( in other words, a showcase of how Bart usually dont behave towards Maggie).