Mark Sloan and Arizona’s relationship started off in Season 5 when Arizona first started dating Callie, we were shown little scenes every now and then of them together but mainly Callie was present with them. Their relationship was not one necessarily born out of friendship with each other but more out of a sense of loyalty to Callie. There has always been an underlying form of hostility between the two due to Marks former relationship with Callie and they have always used humour to cover it up.
In Season 6 their relationship continued but mainly with Callie as a buffer, it was clear at times that Arizona felt jealous and insecure about Marks place in Callie’s life, we got to see this in a deleted Valentines scene with Arizona and Callie where Arizona was worried that Callie wasn’t really gay and was wanting to be with Mark, again we saw this when the issue of children came up, Arizona automatically assumed that Callie was going to be with Mark.
In Season 7 we saw that Arizona had finally had enough of Mark intruding on her and Callie’s relationship, going as far as to ask Teddy to start sleeping with him again when that failed to work we saw her trying to avoid Mark by declining his dinner invitation which led to an interesting discussion between Arizona and Callie where Callie felt Arizona wasn’t giving him a chance to which Arizona told Callie that yes she didn’t like Mark at all using the excuse that it was because he stared at her boobs. In the end it was shown that Arizona for Callie decided to give Mark a chance, telling him they were going out on a date together.
After Arizona’s return from Africa, we are shown Mark and Arizona having several conversations in regards to Callie, we see Mark point out Arizona’s faults to her while Arizona admits to thinking of Mark as her brother. Finally Mark tells Arizona her biggest fault is that she bails when things get hard. After Arizona finds out Callie is pregnant and declares she is all in we see Mark and Arizona’s relationship deteriorate slightly as they try to navigate through the awkward situation of being parents together. Arizona tells Callie that this isn’t her dream, sharing a life, Christmases and so on with Mark is not what she wanted. Later on we see them arguing at the baby shower where Mark tells Arizona not to feel bad that he knows Callie better and Arizona tells him to shut up that he is not the Callie whisperer. At the end of 7.17 we see Callie and Arizona on their way to a bed and breakfast but when Callie insists on using their time to talk to Mark, Arizona has enough and throws Callie’s phone in the back which leads to them arguing where Callie accuses Arizona of being Jealous of Mark which Arizona asks her ‘Can you blame me, he gets most of you’.
During the Musical things finally come to head when Callie and her child are fighting for their lives. It is shown that Arizona is wanting to save the baby where as Mark is not thinking of the baby but only Callie, they proceed to have a full blown argument where a lot of horrible remarks are thrown at each other and it climaxes as Arizona t say’s to Mark after he tells her that she never wanted this “No no no, you know what I never asked for I never asked for you Mark because you know what you are, you’re basically a sperm donor, I mean this is me and this is Callie and we’re together so I say”, to which Mark to the audiences shock cuts her off and replies ‘No, you don’t get a say, this is my family I’m the father, I’m the father, you’re not anything…you’re nothing’. After this we see later on in the episode Mark silently asks Arizona to save Sofia in the operating room which leads to Mark apologizing to Arizona outside Callie’s room acknowledging her as the mother of their child.
In 7.19 we are shown Arizona and Mark getting on, working together and playing nicely where they are swapping shifts between Callie and Sofia. In White Wedding at Callie and Arizona’s dinner Mark makes a speech where he again acknowledges Arizona as the mother of his child, and later on in the episode when Arizona is upset and crying Mark is the one to comfort her. Their relationship has complicated written all over it but they are now bound by Sofia for the rest of their lives by the end of Season 7 it’s the impression of the overall audience that they have put their jealousy’s and insecurities away for the sake of their newly formed family.