Latex smells bad
Even if you're not sticking your nose in it, you can still smell that unmistakeable latex smell when you unwrap a condom. And it's not the smell of sex — it's the smell of a hospital. No bigger libido-killer, IMO.
It's less spontaneous
"Hang on a sec, let me just put a condom on."
But it's never just one sec. It's more like 20 secs, by which time the ~moment~ has invariably lost some of its urgency, its intensity. Which most people are willing to forfeit for the sake of not getting STDs or pregnant, but still.
It's less intimate
When there's a literal barrier between you and your partner, of course sex can feel less intimate. Condoms feel kind of sterilizing — like plastic wrap.
The skin-to-skin contact of condom-less sex just makes you feel so much closer to the person you're with.
Blowjobs really suck with condoms
Raise your hand if you want to give a blowjob to a rubber dildo!
Yeah, I didn't think so. That's because it tastes bad and feels like nails on a chalkboard... if the nails were your mouth and the chalkboard was his condom-covered dick.
Ultra-thin condoms don't make a difference
Many brands make ultra-thin condoms that are supposed to provide the wearer with increased sensation during sex. For the wearer, maybe, but not for the person he's wearing it with.
Ultra-thin condoms or ultra-thick condoms, it's all the same to a vagina.
They make your vagina feel like a desert
Even if you're properly naturally lubricated, even if you're using lube (water-based, with latex condoms!!), even if the condom ITSELF is lubricated, there's just something so drying about latex. Which is bad, because the drier the contact between the condom and a woman's vagina, the more friction there will be, and the more likely it is that the condom could tear.
"Ribbed for her pleasure!" some condom packaging boasts. "New variety pack!" "Warming sensations!"
The vagina, you're probably aware, has ridges of its own. It's not one smooth tunnel; it's got bumps and textures. Ribbed? Don't make me laugh. I can't feel your damn ribbing.
Also, the "warming" lube just burns, OK?