That’s a pretty complicated question and you don’t give me many clues but I’ll do my best to give a helpful answer.
If the baby wasn’t planned, it might have been a shock to him. Maybe he’s doing the best he can but doesn’t actually know what’s expected of him, or what being in a relationship with a baby in the picture actually means. Or maybe he’s afraid you might get pregnant again. That can be a genuine fear for guys who are not feeling emotionally or financially prepared.
If you want to revive the passion, I suggest you gift wrap a packet of condoms and give it to him with a romantic card. Write a note in it telling him you value him as your baby’s daddy but you never want to lose the romance and passion you both shared. I’m thinking that should clearly deliver the message you’re ready to return to a bit of action in your love lives, without the need for an awkward conversation.