In this Money Matters report, Time Warner Cable News’ Tara Lynn Wagner talks to an attorney about why it is important for some couples to have a prenup.

You are getting engaged and preparing to spend the rest of your lives together but just in case “I do” someday turns into “I don’t,” you might want to have a prenup.

"Is it romantic? Absolutely not. Is it necessary? In many cases, absolutely," says Laurie Ruckel, partner at Loeb & Loeb.

A prenuptial agreement, as the name suggests, is a contract that is negotiated and signed prior to tying the knot. It lays out what happens to any assets brought into or acquired during the marriage should that marriage ultimately end.

"Who is entitled to what components of that property in the event of a termination of the marriage and what happens in the event of death or divorce to that property?" Ruckel explains.

A prenup can also deal with alimony, but what it cannot touch is child support.

"That’s against public policy," says Ruckel.

You may think a prenup is just for celebrities and the super wealthy, but actually, they are more common they you realize. Business owners often seek one. They are also beneficial for blended families, where one or both of the new spouses have children from a previous relationship.

Every prenup is different, but Ruckel has some advice that can be applied across the board. She says it's not something you should spring on your fiancé on the eve of the wedding.

"One issue to upset a prenuptial agreement is coercion or duress, and you certainly don’t want to be bringing that to your partner to sign on the way to the chapel. So we don’t sign then, we don’t negotiate then," she says.

She also recommends each party have their own attorney who will look out for their best interests.

"I highly, highly recommend to my clients that they speak to their fiancé about separate council, and council who specializes in trusts and estates. Not the brother-in-law who's done one real estate closing," says Ruckel.

While it may be an uncomfortable conversation to have, she says it should not make or break the relationship. In the end, it is just another legal document.

"Does it connote failure or a concern about doom and gloom? Absolutely not. You’re going to be together, I hope, for the rest of your lives, and I really want this to be something that ideally you put in a drawer and it’s like, you bring your umbrella and it doesn’t rain," Ruckel says.