The act of taking a shit on a woman's chest (asleep or not) then adding coconut topping and finishing it off with a hot syrupy ejaculation that represents the hot fudge sauce.
You can rub "your banana" in it if you so desire to make it extra realistic.
Man 1 "Dude I performed the Samoen Sundae on my gf last night for the first time."
Man 2 "Wow dude thats gross, how did she take it?"
Man 1 "Well she was fine with it until the 5th time I did it to her and she woke up."
Man 2 "You did the Samoen Sundae 5 times in 1 night!?"
Man 1 "Yup"
Man 2 "You're a Haus dude"
The act of taking a shit on a women's chest and then sprinkling coconut on top of it, then ejaculating on it for the simulating the hot fudge sauce.
Man 1 "Dude I was with my gf last night and laid a samoen sundae on her for my first time"
Man 2 "Damn dude that's gross kinda gross what did she say"
Man 1 "Well the 5th time I did it she woke up"