That title is pretty misleading, actually. Princess Princess is not particularly yaoi-y. The man kissing scenes consist of the male characters doing it to troll. Rather, it’s more of a delicious trap anime. The main characters are forced by their all-boys school into becoming delicious traps because well, the school does need cheerleaders and culture festival waitresses and whatnot.
The show is kind of fun because two of the princesses, Touru and Yuujirou basically go “Well, if I’m going to be forced to be a princess, then there’s only one thing I can do: I’ve got to own it.” Mikoto, on the other hand, does not want to be forced into a being a trap. Besides, he has a girlfriend! The irony is, of course, that the princesses are more woman than she’ll ever be. She’s kind of dull and boring next to the delicious traps. Were Princess Princess actually yaoi, Mikoto bitchiness would probably cause one of the other male characters to grab him by his tie and say “Ikanaide!”, followed by some implied buttsecks. But since Princess Princess doesn’t go that far, ultimately his personality just serves to make him a general sourpuss who wants to spoil everyone else’s delicious trap fun.
The show is forced into a bit of a tough position. The show really only has about four episodes of actual material where you can laugh with the show, rather than at it. Had they gone that little bit further with the whole quasi-shudou/onnagata/nanshoku thing, it might have provided a little more opportunity to laugh at the show and maybe stretched out the useful material some more, but it also would’ve probably made it harder to laugh with the show.
Would I watch it even if I weren’t forced? This is the reason I only watched on episode of this for the lulz back when it actually aired.