Kevin O'Leary has some relationship advice: When dating someone new, in addition to listening to your heart, you also have to listen to your head and talk about finances, says the star of ABC's "Shark Tank."
"Everyone likes to fall in love," O'Leary tells CNBC Make It. But "fast forward three years. The reality of life sets in and who's the new partner at the table? Money. You do not want to break up because of financial stress."
"Great couples, great relationships, are built on an emotional connection; no question about that," he says. But "you want to stay together for a long time? The pillar of strength in a relationship? You got it: money."
That doesn't mean that in order to have a good relationship, you need to be rich. Instead, O'Leary says it's about finding someone with the same financial objectives as you.
"Money is going to be with you the rest of your life. Even if you end up marrying that person or coupling with them, money becomes your partner," O'Leary says adding that, "More than half the time the reason people break up is they're not compatible financially."
Indeed, the leading cause of stress in a relationship is finances, according to one study by SunTrust Bank. And another study found that the way your romantic partner spends and saves directly affects your own well-being.
So don't be afraid to talk about it, and talk about it early on.
"It's a little early on the first date," O'Leary says. "Second date, maybe. But I'll tell you by the third date — if you're actually going through the third date and you start to like that person — you've got to start talking about money.
"Just ask what people's aspirations are ... where they see themselves in five years," O'Leary says. "How much debt do they have now?"
Find "somebody that has your same financial objectives," he says.
And when you do find that person, O'Leary warns against buying an expensive engagement ring, as you'll get more out of that chunk of money if you invest it.
It's the same with a lavish wedding he says. In fact, for his own wedding, he and his wife Linda opted for beer and pizza so he could invest more money into building his business, which paid off in the end.
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Disclosure: CNBC owns the exclusive off-network cable rights to ABC's "Shark Tank."