I think you might be thinking of "Private Call"? https://www.mangago.me/read-manga/private_call_yaoi/
Alpha's name is Jihwan, but the omega has pink hair. Alpha does have a vasectomy b/c he's a male escort, and it does reverse itself.
Summary from mangaupdates:
"In a world where alphas and omegas are the stuff of urban legends, Doha is a rare dominant omega who usually deals with his heat cycle through casual one-night stands. One day, he uses a matching service and gets paired up with an alpha named Jihwan. Things get unexpectedly intense. Overwhelmed by pheromones, Doha forgets about precautions and ends up knotted, leaving him in shock. However, Jihwan seems entirely unfazed by the situation and boldly suggests they meet again, saying, "Don't tell me you're scared because I'm an alpha...""
OH DANG!! i was off by a bit BUT THANK YOU OMG!!! i hope your food will always be tasty and that both sides of your pillow are cold
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guys do yall know the name of this bl omegaverse, ive been trying to remember it cos it was cute. the top had black hair and looks kinda sharp and i think his name was jinhwan??? or smth close to that and the bottom was yellow blond. they have a kid and like idk if its the same story but like top had a vasectomy apparently that got reversed. i WANNA READ IT COS THEY SEEM SO SWEET BUT IDK THE TITLE PLZ HELPPP