Futari de Papa Hajimemashita

Before transferring to New York, Nogi Shinjiro confessed to his crush, Aoyama Yuki, and was rejected for not being gay. Nogi came back from overseas after 2 years and is surprised go see that Aoyama has a kid now. What happened while he was away?
Note: Contains the extra "Sannin de Kazoku Hajimemashita" (三人で家族はじめました).