Anyone who has any experience with one knows: Vaginas have liquid coming out of them. This is especially true if the owner of a vagina is having sex. Depending on the person, there will at least be some of the liquid coming out of the vagina at some point in the process. Some kind of absorbent padding will almost always be helpful in preventing stains. This is especially important if you think there will be some ejaculation, squirting, peeing, or period blood coming out at any point.
I made this mistake a long time ago when I fingered a woman on her period and got so much blood everywhere when she squirted that it soaked through the sheets and into the mattress, which required bleach to soak into it overnight.
Put something down to absorb it even if you don’t think anything will come out. Something might when you least expect it, so be ready for the flood.
It’s really not that wild. Towels mean you don’t have to change the sheets and the mattress topper if you’re lucky enough to have one of them.
Also is good for the lube. I don’t see a problem here.
Towels mean no one has to sleep in the wet spot
There isn’t always a wet spot.
If you can guarantee that there will be no fluids leaked or excreted by any participant , then sure, no need for precautions.
That’s why you talk to your partner first.
Having towels around is great. Recommended even!
Pre-emptively assuming a woman is going to ruin your mattress and making arrangements without talking to her is what has ruffled some feathers here.