There's not a single time in which either of the two characters explicitly expressed happiness when they were together. Can you really call this love?

Every instances in which the characters seem to have romantic feelings all had a scientific explanation for (in the fictional sense, not actual science. made up by the author). For example.....

1. Even at the end when Li Li seeks Xia Mian for a hug. It was explained that this was due to Li Li's pregnancy and the offspring's need for the alpha pheromone during pregnancy.
2. Even when Xia Mian was wondering why he was still sexually attracted to Li Li even after Li Li's glands were destroyed (and lost his pheromone scent), it was explained later that it was because their s*x hormones had a 90% compatibility rating.

From the beginning, their relationship started as a "friends-with-benefits" type of relationship due to the biology behind the ABO dynamic (being 90% in fertile compatibility).

In the first three years, there was signs of relationship development as they eventually started living together and Xia Mian seemed to even consider marrying Li Li. Their relationship was rather harmonious and normal. But beyond that, this novel didn't really give much insight into the feelings of these two characters. How they felt during the day-to-day interactions of living as a couple (what it felt to wake up together, to hug, to cook a meal for each other, etc)

Much of the past is told from the MC alpha's (Xia Mian) POV. Xia Mian made it quite clear that his interest is mostly due to s*xual attraction to Li Li's pheromones. There's really nothing else in Xia Mian's narration that gave me the impression that he liked Li Li as a person. I believe that both Li Li and Xia Mian sought emotional comfort as they were shown to be quite lonesome (Li Li was looked down by his classmates and Xia Mian lacked a sense of belonging after his parents divorced).

These were two lonely people who sought both emotional and physical comfort from each other. However, I don't see this as a basis for a genuine heartfelt relationship.

Even after they rekindled their s*xual relationship 8 years later, there still lacked an emotional connection between the two.

1. Especially with the New Year's scene when Xia Mian invited Li Li to his family's New Year's dinner. It's a rather thoughtful gesture, but I never got the impression that he developed romantic feelings for Li Li after they rebooted their s*xual relationship.