@thebitterfig: I think, in your scenario, that conversation would've probably gone better. However, each of them being who they are, I think they would eventually have broken up over the same root issue anyway. The bottom line is that they may have started out wanting the same things out of their relationship, but in the end they didn't. Stan in particular seems, to put it as charitably as I can, to be confused as to what kind of relationship he wants. He wants to call himself Lisa's boyfriend, implying a relationship beyond FWB, but at the same time, he still wants the option to "flirt [and] fuck" with others. Sooner or later, that disconnect would come up. It may or may not, depending on the circumstances, have been an angry conversation, but in the end it would've come down to "Sorry, I like you but this isn't working out."
That said, the bit about finding a decoder ring in a Cracker Jack box cracked me up.
Welcome, and please stick around. ♥