1. When you're having sex and you go harder and deeper. This is pleasing to most women. They usually yell, "FUCK ME HARDER."
2. When you're fucking and you're slamming down hard on some wet pussy. Most effective in the missionary style sex position. The man's legs are together while the womans legs are open wide. Man slams down deep every thrust.
1. "I gave Jessie a hard fuck last night." "Really? Did she scream?" "Yeah, she said "FUCK ME HARDER DADDY! HARD FUCK ME! HARD FUCK ME! FUCK MY PUSSY HARD! HARDER!"
2. "Man that hard fuck sex style makes my hips hurt the next day."
Female: "I got hard fucked last night. I didn't think his dick could go that far in! I squirted too!"