Refusing to use a condom is a massive red flag. Yes, they reduce sensation, but they also protect both parties from significant health risks. An IUD is irrelevant to him at this stage
Always use a condom until you have both tested clear and are committed to each other. If your relationship is poly, then condom use and testing is required for every new partner, and it’s sensible to have everyone retested when someone new comes into the relationship.
I’d personally be concerned about their behaviour, either then trying to coerce you into unprotected sex, or being a whiny shit refusing to use a condom. Both of these would make me consider withdrawing consent, but I’m a stickler for enthusiasm at all stages.


If you fancy a small change over to comic/graphic novels, I can highly recommend the Alan Moore run of Swamp Thing. Two years ago I would have also included Neil Gaiman’s Sandman, but it seems that he’s a piece of shit, so if you do want to read his stuff, please pirate it to avoid giving him any money.