Imo the only problem with this choice is that the magnitude of it is impossible for the player to tell. I feel like the first sex scene is pretty important in a romance arc (I mean, the characters are literally climaxing
) and whether you get it or not seems to hinge on this single choice. As I said, I think it's a very immersive choice. But what's missing is a little feedback for the player. If I remember correctly, Lucy has basically the same reaction to both choices.
Like e.g., if there's a hidden "housefire" variable, it would be nice to know that I'm moving in the direction of the bar burning down and Lucy getting killed. Maybe the PC burns himself, while playing with matches, so the players know that they should be careful and not play with fire.