I think you have to figure out how serious he is about this. Because, yeah, it's not normal. Maybe he doesn't realize how off-putting this idea sounds. In his mind he could have no issue with having more of the financial burden, and thinks that pleasing him would be something you both would enjoy and it would make you feel less guilty about not contributing? I..don't know. I would say it's still not a very healthy outlook on sex.

But I would try to have another conversation about this to figure out how serious he's being. I mean, if you flat out tell him "this will not be happening" I'd be interested to see what his reaction is. Maybe say something like "this evening after dinner I want to sit down and talk about our finances, would that be ok?" You're going to have to clarify that you are not going to involve sex in any way in planning financial responsibilities and that you insist on coming up with a different solution, related to housework, or related to what type of financial contribution he expects from you (which may mean a different job). If you can't reach a compromise with anything but "give me blowjobs" then I think you have a real issue. You'd probably start with a marriage counselor.