lmao the other guy Hideya she doesn't even love her and mocks her inside his mind how easy slut Kaede is falling for his sweet talk. BF found out because her friend lead him to the hotel she was at because unlike her friend she couldn't stop her affair.
Time skip and she gets a child and marries her BF who stopped his long distance relationship because of his previous job and once he goes to work passes by the other guy does nothing, He is back for his wife but just like the year with him doing nothing he walks away as she finds out the other guy is back.
This was a rip off of Fork in the Road, inexperienced GF gets taken by a known womanizer and takes advantage of her loneliness due to her long distance relationship with her BF to the point of the antagonist sweet talking the GF into saying to love the ntrguy with the only difference that the baby looks like her husband and that the other guy returned at the end.