Since seeing them live for the first time on the Australian leg for the On with the show tour I was quite intrigued by their dynamic as I have only ever enjoyed FMs music and knew little about the bands soap opera especially as it was pretty affectionate for that part of the tour.
To say it is 100% all an act I think is untrue and unobjective. From what I see of LB he has generally a lot of integrity and honesty about who he is and how he feels and I think there is still genuine feeling there on his side, perhaps even if just nostalgia. He initiates 80% of the affection and often kisses SN in the dark and out of the spotlight, its not her with her hands all over him which you would expect if it was all acting.
When Mick was trying to get LB to move his microphone closer to SN for the Unleashed tour "so they could look into each others eyes", LB he said no way- therefore he only does what he wants to do, he's not pressured into anything.
LBs response to his Charlie Rose interview when asked to define his relationship to SN is so very telling. And his tears in response to when she crys during Say Goodbye in Vegas 2013....there's still a lot of emotion/ feeling there, these examples are clearly not acted or fake.....

Lindsey didn't say he told Mick "no way." Although, I'd agree Lindsey is not forced to do anything. I mean, if you listen to him they forced him to use a guitar pick, which ...

Michele

Exactly.... I just don't think LB would be affectionate just to get ticket sales. He isn't that kind of a fake guy. Plus very few people are obsessed with their relationship, 90% of FM fans are there for the music alone. People wouldn't stop going to their concerts if there was no interaction and they know that.
I think that they often feel real emotion on stage, LB especially.