To be fair, I don't think dude is actually as hung up about how she looks as she is, it's the opposite problem - but rather than disengaging, dude needs to find a way to engage her and get her relaxed enough to be re-interested in sex.
If that's not possible, I've got no judgement. Some people make it really easy to seduce their minds back into playing around and some people make is completely impossible and I don't know enough to advise.
Thank you.