To get him to marry you, give him an ore (a mineral from the mine) every day at 11 a.m. at the blacksmith shop (make it a routine). . Note: Start with new game to make it easier. He really likes silver and junk ore, but any ore will do. If you do this every day and attend the heart events, his heart color will change every season. If you keep doing this all by the end of spring or approaching the end while mining in the lower levels, you will find him there walking around. Talk to him and he will say something similar to "I'm just mining for some Silver Ore..." If you have one, give it to him. He will say that he will treasure it. Continue with your normal day. When you give him an ore on that same day, he will talk to you differently and his heart color will change to light blue. Keep doing this routine in the morning every day and he will love you in no time.