The actor spoke with Mario Lopez on Access Hollywood earlier this week about expecting a baby with the pop star and their engagement.
When Lopez asked if they wanted to know the sex of the baby prior to birth, Asghari replied: "That's up to [Britney], but I don't want to. It's something that I want to wait for."
However, the soon-to-be father already has an idea of how he wants to parent.
"If it's a daughter, it's going to be the most spoiled princess ever," he said. "If it's a son, it's gonna be the toughest son. I'm gonna be tough on the kid."
He also revealed that he paid for the 4 carat diamond engagement ring with his own money -- rather than, as he said, have a brand gift it to them for advertising -- but wouldn't spill any details on the engagement story itself.
The couple first announced they were expecting a child together on April 11: