You get the last scene with Lou, if you go and talk to him again. There will be a new dialogue option, which will lead you down the path to the last sex scene with that character
Thank you for the hint. I was able to get there. I also found a route where there is a scene between Lou and Ben, but I feel that am still missing one scene with Bo. I only have three scenes with him... and one last interrogation mark to beat the game ;-)
You can only get the last one if you have a perfect playthrough, that is, you get all 4 scenes with each character in a single playthrough. the last scene is however pretty special, so I would keep working to get that one
