Incestuous?

I was remote surfing and I happened upon this teen movie, Drive Me Crazy. I got reeled in, not because of the plot which dealt with the popular girl crafting a faux relationship with an outcast to get a guy back. The premise has been done much better in Can’t Buy Me Love and 10 Things I Hate About You (in a somewhat inverted manner). What reeled me in was a young Ali Larter playing a somewhat marginal role, as a redhead, but I do digress. The reason I admit watching this movie was the ending twist – no not the girl and outcast falling for each other – that was preordained in teen movie lore. In this ending, the girl’s mom and outcast’s dad end up getting together, and want to move in together. And the girl and outcast, now in love, seem unphased. They do not think of the incestuous implications if their parents are cohabiting, and perhaps even marrying, while they also date. Granted they are both off to college, but still they will all be living in one house during the summers. This was the exact same scenario that has heretofore prevented the lovelorn parents in Gossip Girl from getting together (although in GG they have consummated their longings, and GG does involve the in-girl and the outcast, but their romance was a traditional one from the start not a faux one). In GG, the daughter actually pled with her mother not to get together with the outcast’s dad and did not intervene when said mother entered into a loveless marriage with a Trump-esque character all to protect her relationship (which at season’s end had ended and finds her now dating her best friend’s ex-boyfriend who the in-girl had hooked up with while her best friend was still dating him). So why does the potentially incestuous scenario cause such concern in GG but not DMC? And is it actually incest? Who says pop culture is meritless when it poses such profound questions? And don’t even get me started about the movie, Clueless, in which the Alicia Silverstone character falls in love with the son from her father’s first marriage.