Letting my man drink my breastmilk.
Oh this would be a huge list for me. There's few things I haven't done sexually (hard limit on kids or pets but little else). Just to name the easy ones:
Knife play
Blood play
Blood drinking
Manual choking
Hand over mouth choking
Ligature strangulation
Biting
Face slapping
Spanking, flogging, cropping, etc.
All restraints
Forced gagging
Forced vomiting
Forced wetting
Enemas
Watersports
Anal everything
Fisting
Three ways (all genders)
Group sex
Public sex
Verbal humiliation
Branding
Scarification
Needle play
Age play
Puppy/kitten play
Orgasm on command
Orgasm denial
Role play
24/7 power exchange
Boot/foot worship
Sex on various substances
Sex while unconscious
Rape fantasy
And many, many more.
^I've been on the receiving end a couple times and the giving end once. First time we sterilized a pocket knife then held the blade over a flame until searing hot and used it to make a kind of star design by pressing the tip against clean skin repeatedly in a circle. The second time we used a metal coat hanger bent into a symbol. My brands have since faded considerably over the years. I have more permanent marks from knife play sessions I was not planning on keeping as body art but that have stubbornly decided to stick around (like a checkerboard on my thigh from a sex party where I ended up being turned into a parlor game).
That sounds pretty cool. Are you a slave/submissive? I have seen brands on people made with coat hangers before but they were for a university fraternity.