One more thing...
Recently, my Sims started doing this Double Smooch greeting. I don't know if it has always been there, but it's the first time I've seen it in the game. It started about the time, that townies started wearing random outfits. Anyway, it's an unusual interaction. It never seems to add a pink bar. In that regard, it's not romantic. HOWEVER, to any Sims your Sim has a pink relationship with, it will count as a romantic interaction. It will kill the pink bar & make them either sad, or angry. City Living definitely added some interesting social possibilities, but it seems like there could be some tweaking. The romance festival creates some interesting situations. In some ways, it mixes things up. However, as sensitive as Sims are, it generally just makes a mess of things. If Sims are going to autonomously greet each other, in a certain fashion, maybe they should either get Pink Points, or it shouldn't wreck their existing romantic relationships. It's basically just a noisy secret handshake.
*update*
I noticed something interesting about the DoubleSmooch. It doesn't seem to really register as a speaking interaction, officially. My Sim was talking to one Sim, whom he greeted in this fashion. After a while, another Sim showed up & gave him a double smooch, but she was never listed, as someone that he was talking too. THEN, an odd thing happened. The first Sim left the conversation. I had already prompted him to talk to the second one. They were at a Ruins dance party & Sim one was dancing & Sim 2 was just staring at him. When Sim 1 left, he and Sim2 ran off together. They ran for quite a while, then stopped. They stared at each other, then they both jumped and said, "Yabusabi!", or something like that. Not sure what that was, but there's probably a story there.