Steven cried on it.

While I agree with you and I'd also prefer if Pearl found inner peace by being single, with the way Mystery Girl was introduced, I doubt that will be the last we've seen of her... I guess we'll just have to wait an see...

I was kinda bothered with her condescending and hostile nature, while I can understand why she was like that towards Peridot, with for example Connie I don't see a good reason for her to be. But like I said, I can understand why is she's so untrusting and hostile at the moment and I really hope they go into that in future episodes. I'd say that unlike Peridot, she's rather undeveloped character...

Pearl needs to be with Mystery Girl in order for her to heal. Pearl needs to be confronted, by Mystery Girl, that the only reason she is attracted to her is that she, in Pearl's mind, is Rose 2.0.

As to whether or not this will lead Pearl to stay with Mystery Girl to try and get to know her as her own person, or if  they will break up as a result (perhaps on mututal terms and staying friends afterwards) - who knows?

All I know is that Pearl is nowhere near being over Rose and she needs this. She needs to be confronted over it. Mystery Girl would provide a perfect plot device for this, in my opinion.

Good point. I feel that Pearl's attraction toward Mystery Girl has much deeper meaning than "big pink haired girls are just her type". But still, it's feels way too love at first sight-ish. Even if the relationship does work, I still hope Pearl uses the situation to learn how to be more independent...

At this point it is quite clear that she is just smitten by Mystery Girl due to her likeness to Rose. Purely physical attraction. That is why Mystery Girl needs to make a return. As I said, it has the potential to be a very important experience/lesson for ol' Pearl. One which she definitely needs.

EDIT: Not to mention that there is quite a lot of potential for Mystery Girl to get into all kinds of shenannigans by hanging out with Amethyst. The two seem like they would get along quite well - much to Pearl's dismay! ;)

AND, how will Greg react to Mystery Girl? That could be worth a couple of episodes by itself.

I actually think Greg, being human as well as having a unique perspective into how Gems "work", would be the one to first voice his concern over the whole ordeal. He definitely would be able to tell what is going on and since his and Pearl's relationship has really been mended and improved (compare Season 1-2 Pearl and her attitude towards Greg - she was downright nasty towards him!)

Neither Amethyst nor Steven seemed able to tell exactly what was going on when Pearl got smitten by M.G so I'm not sure either of them are mature enough to realize exactly what is going on. Garnet might, especially due to her Future Vision and her almost Cupid-like understanding of love.

But other than Garnet, there's really just Greg. And I'd like to think he is the kind-hearted type of guy who definitely would want to help both Pearl and M.G.

Back to this Lapis point, if I may. In the real world, there are characters that are untrusting, sardonic, aloof, and socialy unassimilated. Many of those people are that way their entire life, only truly coming out of their shell and being light hearded and genuine for a close group of people in their lives. 

As you say, she has been locked away for thousands of years, and has every reason to be socially inept, and even hostile and untrusting. The gem war happened, to a degree, because some gems wanted to rule the planet of the humans, and others wanted to protect it. Lapis got caught in between it unjustly. Can you see why she may have a problem with humans, and most gems? And she's right to be. Not all humans are friendly, and not all gems. She's got Peridot, Steven, and she really has no need to make friends with anyone else--and that's how people are in real life sometimes. A lot of people keep saying Lapis is in serious need of growth, but why? She can be a powerhouse on the battlefield if need be, she's useful as transporation in an emergency, and she has some pretty funny lines because of her awkward aloofness. 

People need to understand that not everybody will solve all of their "character flaws" in their life, and in a show that's so realistic about the way it approches relationships and whatnot, I would totally fine if Lapis remained the way she is. She's far from perfect, and so long as she isn't detrimenting anyone, she doesn't need to change that much. There's no reason for her to be friends with Connie, or Greg, or Pearl, or anyone really. She does her own thing and that's fine by me.

I think we've had this discussion before on a thread that you made, but again I don't think Lapis necessarily needs an arc. She's fine, for all the reasons I listed above. And two, I'm not saying it wouldn't be nice for a more in depth Malachite arc--especially given some of the slower Season 4 episodes that happened instead (which I still enjoyed), but my point of contention is the "shouldve".