Not everything needs a reason. Not sure why you bothered reading to the ending if you don't like it :v
Lol I read to the end ever though I don't like it as well because I'm mostly in it for the sex.
If you here just for the sex then go to myreadingmanga.info its explicit Yaoi only
You came to read it for the sex, yet you call bs on how there was no explanation on how they fell in love? Something doesn't add up there as I'm pretty sure that lots of people have sex without feelings of love in it...
The last one was the only good one the rest was pure BS i have no idea how they came to fall in love there was no story...BS at its best...............love the last one though