If you have graduated, you can ask him if all his friends and classmates are married or have someone else. Then you said that a friend (female) around you was going to get married and broke up because of the contradiction of decorating the house; Or male relatives and friends you know, because there is no house and you can't find someone, etc ... It depends on his acceptance and your speaking skills. As long as you are right, he should bring up the house himself. Unless he wants to keep it from you.