Genesis was a prideful, arrogant man. So, obviously, he wouldn't enjoy his pride being wounded. Hell, anyone wouldn't like it, but specifically him.
You were a 2nd Class SOLDIER he grew interested in. After all, you were so intriguing, unique! He doesn't have the word to describe how his curiosity was piqued when he met you. He was completely enamored.
There's only one problem. A big problem. You didn't seemed to be interested in him at all.
At first, he just thought that it might be the shock, or maybe you were just too oblivious to pick up the subtle hints he threw at you. But he wasn't exactly a patient man, so his hints grew more and more obvious—to a point where he was pretty sure Sephiroth and Angeal picked up on his interest for you—but you remained ignorant. Intentionally or not, he wasn't sure.
So, he concocted a small plan. While you were walking in a hallway, he made sure to bump into you, making you fall to the floor in the process. He took the opportunity (that he himself prepared) to offer you his hand to help you up.
"I'm sorry, I hope you aren't hurt."