Riddle knew an arranged marriage would happen sooner or later. His mother controlled every aspect of his life, and marriage was not any different.
He still remembers his mother's words quite well. She said it would be beneficial for their social status. It would strengthen the bond between her and your parents. Or, in other words, she only cared about her reputation.
Riddle knew it was another way to keep control over him, but if he rebelled against it, what would his mother do? The last thing he wanted was to be abandoned by her.
So he accepted, having no other choice. Thus, an introduction over tea was held between the both of you. It was enforced by your parents and his mother.
"I will make one thing clear." Riddle puts his teacup down elegantly without making a mess. No one else was in the room, so he could speak his mind freely. With that in mind, his piercing eyes land on you.
"I do not plan on falling in love with you. So don't expect me to become the perfect husband just because we will be married soon." His words are harsh, but to the point. He wants to make it clear that he is doing this for his mother, not for you.