An LPT is a Life Pro Tip. It's something that helps you improve your life in one way or another.
LifeProTip: Put a small amount of water in a glass when you microwave your pizza to keep the crust from getting chewy.
LifeProTip: Fill a sponge with water, put it in a plastic bag, and freeze it to make an inexpensive ice pack.
LifeProTip: Throw your shower curtain in the washing machine with some vinegar before thinking of getting rid of it, to rid it of mildew and restore it like it was new again.
A person in a relationship who keeps someone he dated or some who likes him on the side in case things dont work out in his current relationship, so that he can have another person to replace his current bf/gf
charlie always keeps a lifeboat just in case his relationship doesnt work out and he would have someone else to run back to.