Hm. I suppose it makes sense to say that sex is different because it is a sacred act, but I was under the impression that perverting any action from its natural purpose was sinful. But outside of sex, this does lead to some inconsistencies, so maybe I’m wrong about that.
If sex and sexual pleasure are special, then we’re back to the question of whether making out is inherently sexual. If it’s not, then I suppose it would be licit under some circumstances. Continuing with Prodigal_Son’s line of questioning, if L only applies to sexual actions, and making out is not sexual, then L would be largely irrelevant.
I think what you’re describing is OK. I can’t cite any documents that say so, but I also can’t cite any documents that say it isn’t, so we’re sort of stuck on that front. But if there’s no reason to call something sinful (other than an emotional reaction, since those are unreliable), then I assume that things aren’t sinful until I have reason to believe otherwise.
I really can’t see any reason (other than scandal and the possible near occasion of sin) that calling each other “girlfriend”, going on dates, and kissing would be immoral. I obviously can’t give you the OK (and anyway, I’m sort of biased myself), but I’m really at a loss as to why it might be inherently immoral. Nothing involved in going on dates, kissing, or having a particular form of address need be exclusive to marriage or the process of discerning marriage, so I don’t see why those things would be wrong outside that context.
Again, that’s just where my understanding is right now. I’m not going to pretend to know what Church teaching is on the matter, if a relevant teaching even exists.