I've been thinking about this for a while (spoilers if you still haven't seen Dark of the Moon)
1. In all the movies, Sam is running after a girl, running with a girl or rescuing a girl. While trying to attract Mikaela in 07' might be okay, what if Bumblebee doesn't think so during their next adventures? (ie, "Why can't he just stay with me?"). This could also apply to Soundwave and Dylan as Dylan pursues Carly (or any other girl because he kinda seems like a ladies man)
I wasn't thinking of slash, though it could be read/interpreted as such. Here goes:
1a. Serious fic. Cybertronians bond very easily to other species (read: Headmasters, Autobots & kids, etc). After a while, they become kind of like siblings/best friends all mashed up into one special bond. But humans are always the ones to ignore their guardians/friends for whatever reason. When that happens, the Cybertronians will fall into a kind of depression and/or:
- 1a.1 Act out like a little kid
- 1a.2 Do their best to remove their rival for their human's affections (I think Soundwave would do this -- the only way he really knows how to)
- 1a.3 Try and win their humans back with affection, gifts, racing etc
So what would Bumblebee do? Soundwave? I guess this could be open to any continuity, but movieverse is the only one where the Transformers are constantly ignored in favor of something else.
1b. Crack!fic. Transformers are like Puff the Magic Dragon, and their humans are Jackie Paper. If they ignore/forget about their 'dragons' they cease to exist. That song made me cry when I was little. The humans can either be kids or not, and can 'grow up' or not.