OK...so sucking dick, eating pussy, fucking and..perhaps Greek on the woman can all be deemed "regular" sex. Where does anything else get placed?
Pegging the man's ass with a strapon?
Enema Play?
Whips?
Restraints?
Cuckolding -Eat that stranger's cum from her pussy little hubby!
Flogging?
CBT?
Orifice enlargement via toys?
Swinging with other couples?
Men taking it from a tranny?
Watersports?
Lactation lust (i.e. men nursing on breast milk)?
Pooping in an oversized diaper for a make-believe Mommy?
Genital slapping?
Genital piercings?
Testicle/nutsac stretching?
Orgasm strangulation?
Electro play?
Anal with pee?
Crossdressing?
Semi or public sex?
There's so many but where do you draw the line between standard/traditional sex......that which sounds "different but doable... that which would require encouragement/convincing and the things you'd say No fucking way!