3L8TM is a stylized representation of the phrase "I love you." The "3" represents the word "love," as it is the third letter of the alphabet (C), while "L" stands for "I." The "8" corresponds to the word "ate," and "TM" typically indicates "trademark," but in this context, it might simply be part of the playful wording. Overall, it’s a creative way to express affection in a digital or text format.