This. Prerecorded video is one thing. Once you engage the person it's crossing the line.
When there is conversation then he emotionally bonding with the big breasted bimbo. That's energy spent on her and not you.
Personally, there is only a "line" if one person draws the line. I think it is all one slippery slope with no lines until people draw them.
I am very pro-marriage and very pro-commitment to a marriage. I was in a Sex Starved Marriage where my wife refused to have sex with me. I knew that "keeping it in my pants" was important to me, my self respect, and my marriage.
I imagine that the slippery slope can range from
fantasizing while day dreaming,
sex phone lines, cam girls
strip club private dances
massage parlors with happy endings
escorts, paid sex workers
a NSA F-buddy
I think that a couple should decide what their boundaries are that they can both live with. For me (being old fashioned) it is pretty traditional.
My wife and I found compromise and worked on changing our boundaries so that we can be happy together. Our compromise involved just us, but having been where I was and having contemplated divorcing my wife over a lack a sex, I am more understanding to the pressure on couples that want to remain together and yet have sexual gridlock issues.
Still there are interesting discussions on Monogomish and how a committed relationship may not be the traditional one. I suggest the following as worth of thinking about. https://www.youtube.com/watch?v=0sYguTPLpHE https://www.youtube.com/watch?v=P2AUat93a8Q
I don't think that there is any "one solution for all couples."