The 98 Degrees singer - who divorced Jessica Simpson in 2005 after three years of marriage - explained he didn't want to fail in his proposal to the 30-year-old beauty by "setting the bar too high".
He explained: "You gotta take it in stages. If you set the bar too high then you set yourself up for failure. This was a carefully calculated plan. You have to set the romance but you have to take it in phases. This was phase one."
Despite the romantic proposal, Nick - who has been dating Vanessa since 2006 - admitted when one knee gave in, he had to go into "full begging position" when popping the question.
He added to US TV show 'Entertainment Tonight': "One knee wasn't enough so I had to go into the full begging position. And plead for her hand."
However, the pair are in no rush to get married.
Vanessa explained: "We're enjoying being engaged. Everyone rushes to the next step, and I like this step."