Ben Affleck and Lindsay Shookus' relationship was ''good but complicated''.

The 'Batman v Superman: Dawn of Justice' star split from the 'Saturday Night Live' producer recently but despite their break up, their relationship was always ''really really good''.

A source told People magazine: ''When it was good it was really really good. When they were in the same time zone and not focused on other things it was good. It became incredibly complicated with their families, with their jobs. He really liked her. He loved that she was smart, funny, opinionated. When they were together it brought him a bit outside of his comfort zone. She brought a bit of fresh air into his life that he needed.''

Ben recently admitted himself into a rehabilitation facility following an intervention from his estranged wife Jennifer Garner - with whom he has children Violet, 12, Seraphina, nine, and Samuel, six - and he is said to be doing really well.

A source said: ''One of the key elements with taking control of your addiction is knowing when to seek help, which he did, and it is a major step in the right direction. One crucial aspect of Ben's recovery is for him to be able to seek help when he feels as though he is not in control - when his ongoing treatment and meetings with sober coaches aren't quite enough. The best case scenario is for him to seek help, which he has done willingly, and for that, we are all very grateful and hopeful.

''Addiction is not something that goes away. Every day is a battle for recovering addicts, they are fighting for their sobriety and to lead healthy, balanced lives every day. Ben has been working incredibly hard for the last year to follow a streamlined program designed for him and his journey. He has been attending countless meetings, has continued to work with sober coaches and does his best to follow through with the things that will help him maintain his health.''