Disclaimer: Naruto isn't mine as well as 1001 Things It Means to Be a Dad
Being a dad means discovering that living with a pregnant woman is a lot like living with a woman with PMS. Only she's heavier, moodier, and the symptoms don't go away in a week.
Kakashi had dated women. His biggest dislike about them was during PMS. They bitched, they complained, they loved you one moment and hated you the next. Some of them also got noticeably fatter.
Then he fell in love with Iruka. None bitchy, no complains, always loving, always on the borderline between plump and skinny, with one or two muscles.
And then as someone wanted to ruin all his plans, Iruka got pregnant. And Iruka got heavy.
"Why are you looking at me that way?" Iruka asked as he put on his pants.
"What way?" Kakashi said from his spot in the bed. Iruka had awaken at five, awaken Kakashi at five-ten and got caught up in Kakashi's idea of morning fun until seven.
"The way guys look at fat girls."
"With the utmost love and care."
"Guys who aren't chubby chasers or fat themselves."
"Babe, you know I love you more than anything. I don't care if you're fat or not." Kakashi said pulling the covers up. He was going to back to sleep in the warm, comfy bed.
"Sure you do."
And then Iruka got moody.
"Kakashi, where were you?" Iruka asked sitting at the kitchen table, drumming his fingers.
"Working." Actually no. Kakashi was at the adult store, picking up books and having a browse.
"You were cheating on me, weren't you?" Kakashi took a step back. Those were the kind of things his ex-girlfriends used to say during PMS. Iruka never once(verbally) doubted Kakashi's love for him. "I can't believe it. After everything we've been through." Iruka began to sob and laid his head down on the kitchen table.
Kakashi took the seat next to him and put his arms around Iruka. "Babe, you know I love you and you only."
And repeat.