On top of the sheer WTFery, this makes me wonder if maybe John expected May to try to get pregnant or otherwise fight dirty to keep him. That was how he ended up married to both Cynthia and Yoko, and I think it would have made it easier for him to truly split with Yoko if someone else was making the decision or if he felt like it was out of his hands. Maybe, irrational as it is, John interpreted May acting like a normal responsible adult as a rejection - guess she doesn't really love me if she's not trying to trap me here forever! While it feels like an oversimplification to bring everything back to John's parents, you do see that pattern in his life repeatedly: he wanted people to fight for him, to compete for his attention, and to demonstrate their love by playing mind games or seeking to control him. (There's a strong Mimi influence there as well - the one who *did* fight for him.) As lovely as it is to imagine the alternate universe where John married May and lived happily ever after, she was probably always going to be too well-adjusted for him.