You should always say I love you to who you love everyday, whether a significant other or not because you won’t be sure when you will be able to say it again. But in a relationship, it is really important to remind them that you love them. They need to know what you still care and that you’d move mountains for them. Everyone needs to feel some love and hearing those three words can make anyone’s day. You just want your partner to know how much they mean to you and you can’t make them think that you love them any less. Tell them you love them everyday!