It's less the acts and more the effects - anything which does not support and foster good mental and physical health has to be a no-no. This will vary from relationship to relationship.
Anything non-consensual.
I'd also personally draw the line at scat, vomit, blood-letting, needles, most kinds of D/s mind-games, anything which causes Mrs M pain, or triggering her gag reflex. But that's just me, and I wouldn't necessarily label many of those "perverted".