When you arekissing someone and you start sucking in your air to create an almost vacuum seal with the other person.
Did you just do the Kylie Jenner lip challenge, your lips are looking plump?
No, I have just been using the eastern slopesuck as my favorite make out method.
n: the unfortunate occurrence of sweat build up between the cheeks of one's anus. This causes an unsettling lack of friction, and often a concern that the victim has shit them self. It is usually caused by heat and excessive walking, and is often paired with a Slippery Slope. Can be cured with toilet paper or, for the more daring, a self-induced wedgie.