Let’s Make a Baby by J. D. Light

Gates is in love with his best friend and roommate Fletcher. He’s tried to date… well, he’s thought about it, but in the end, the idea of settling for some other alpha leaves him feeling cold. He knows someday Fletcher is going to find and fall in love with the omega of his dreams and the only way Gates can survive that when it happens is if he has something in his life that he can put his whole focus and heart into. So, he sets out to have a baby of his very own.
Fletcher is in love with his best friend and roommate Gates. He doesn’t want anyone else, but he is also terrified to say something and ruin what they have. But when Gates comes home with pamphlets on having a baby, Fletcher’s only thought is that the baby has to be his. So, he offers up a solution. They make a baby together and raise it as friends.
When it comes time to actually make a baby, the agreement is sex until pregnancy, but lines get crossed and things change. Something they thought they’d never get might just be in reach.