Baby Steps by Catherine Lievens

Laurie is only nineteen, and he has no intention of growing up anytime soon. His family still treats him like a child, and as long as that means he can continue having no responsibilities, he has no plans to change.
Alexis has everything planned. He’s studying in college, working as a babysitter, and enjoying himself while keeping an eye on his goals.
Neither of them expected their life to change, but it does.
When Laurie finds out he has a daughter, he’s tempted to run away and never look back. He would have, if her mother hadn’t dumped the baby into his arms for the day and left. Meeting his mate while at the grocery store to buy diapers makes an already terrifying situation even scarier, but Laurie knows he doesn’t have a choice.
He has to grow up—for Melissa, for Alexis, but also for himself.
Hopefully, Alexis will give him time to do that, because now that he’s met him, Laurie can’t imagine losing him.