What was the whole point of Steve/Jimmy coming back in season 5?

New watcher here.. Just began season 5 and I got to the point where Steve comes back and is somewhat present in Fiona’s life again. It kind of made me somewhat pissy with the show because Fiona had just gotten out of jail, she’s been happy, has a solid job, and now is married to Gus. I didn’t see any reason why as to why Jimmy had to come back into her life again. Like seriously? All he did was lie to her the entire time they were together and hid the fact he was married himself from her to a Brazilian girl who needed to be married to him to hold her visa status in America.

What do you think the whole reason was as to why he came back? It seemed like he wanted her to run away with him and get involved with one another again and for some reason he thought he had a shot at getting her back after (assumingly) being gone for a few years.