Most people dream of finding the kind of love that lasts a lifetime, but very few actually get to experience it. Sally and Joseph Littlewood — 99 and 98 years old — are living proof that it's possible. AdvertisementAfter 75 years together, this couple's best marriage tip is quite unexpected. People always have arguments, and in 75 years, we are going to have had a lot, but the key is to move on," said Sally. If you are going to move in with someone, or marry them, you have to know you love them."