The Invisigal Romance is not centered around Sex and Lust
There seems to be a common fandom misconception that the Invisigal romance route is centered around "Sex" and "Lust" because there is a dream sex scene as well as a multitude of sexual jokes and references.
In my opinion, this is mistaking the trees for the forest. (Another Invisimech made this comment, but I do not recall who. I just think it fits.)
First, and I don't know why this needs to be said, many relationships do have sex as an important component. Robert and Invisigal do have chemistry together, and are obviously attracted to one another. This is reflected in canon and in fandom work.
On to the meat of the discussion:
Sex Jokes
These are a facade. Courtney uses them to hide from situations and to defuse tension. In some ways they are a bigger super power than her invisibnility.
- She does not actually watch famous people have sex. This was a joke about how she could only view her power as evil.
The Dream
People like to act like this was crazy and out of left field. It is unfortunately pretty normal that people can't control their dreams. For Courtney to have someone show kindness to her, it translated into something that was easier for her to interpret. She has been used to being treated like a villain, so these acts of kindness and pep-talks from Robert come as a shock to her system.
Bathroom/Mech-Suit Maintenance
Now this is something she can control, but we refer back to what I was mentioning about how she was used to being treated. This is a test for her to see how Robert responds. She is pushing the boundary in their relationship. Does he just see her as a sex object? Does he see her romantically at all?
To a lesser extent this also happens in Royd's workshop.
Culmination
This all builds until the end of episode 4. Robert can choose to show up to the movies with her. An action that she didn't anticipate. There is surprise and happiness plastered across her face, but almost immediately you see her start to slip into these old patterns cracking a joke about how she won't sleep with Robert.
To which Robert promptly shuts down. The insinuation being, that he is there because he sees her as a person and wants to spend time with her.
I wanted to express some of my thoughts on this topic. If you have anything else to add from later episodes, feel free. Looking forward to hearing what you all think.