To remain in love for a lifetime: listen actively to your partner, ask questions, give answers, appreciate, stay attractive, include your partner, give him/her privacy, be honest and trustworthy, tell your mate what you need, accept his/her shortcomings as who they are, give respect in all things, never threaten to leave, say 'no' to adultery, and cultivate variety in your activities to keep things fresh. You can never say 'I love you' too many times and you should say it every day. Even though you've been together forever it seems, you should still continue to 'date' your mate and find new ways to fall in love with them every. Single. Day.