IHTN is a short term for someone who has to nut, meaning "I Have To Nut." Sometimes also replaced by IHTC meaning "I Have To Cum" or IHTE meaning "I Have To Ejaculate."
Sally: Hey John, can you come over and play Roblox?
Bro since I got dirtpilled on Tuesday I have made sooo many worm friends and made them soo many little houses to get married in. Me? Lonely? No you’re the lonely one u lawnowning freak