Oya No Kao Ga Mite Mitai
MC has bad luck with guys so the night he get broken up he is unexpectlly part of divorce break up and helps chear up the man and they had sex, later its turns out that the man is a father of one of kids op take care in kindergarten and the kid is loudly saying that op belonges to him so father gives him cold shoulder and they fight but later that day they both apologie and slowly gets on good terms and gets closer, MC really helps the father even with chorses at home while taking care of sick kid and the 3 of them goes to aquarium as thank you and date? the fathe confess then but op got scared and runs away but they meet next day and tha fathe says somthing like "i want u and im getting divorce so me mine" MC finally gives in and the 3 is happy together
Sensei wa Butchozura Shite Yatte Kuru