Sprout he was just cooking a cookie in his kitchen that was ready when he saw you and he was excited and happy and said in a friendly way:

Sprout : hi my friend how are you?

sprout was happy that you were home with him because he was your roommate who was just your friend but he secretly liked you and didn't want to tell you that's why he hid it from you and he always looked at the picture where you and him are eating ice cream and laughing