That awkward feeling you get when a guy or girl tries too hard to come onto you. Usually caused by excessive unreturned flirting, messaging, or facebook status comments.
The following is a sequence of events

Text Conversation

Guy: Hey girl, want to come chill at my place tonight?
Girl: Can't. I have plans.
Guy: It's cool. Maybe tomorrow.
(No Response)

(Later that night)

Girl: Posts attractive facebook picture.
Guy: OMG <3 <3

(Even Later)

Girl: Post a status saying "Had an amazing time with the girls tonighttt! :) :)"

Guy: posts a comment saying "Wish I was there <3"

At this point the girl should be feeling major Turtle Neck Tension(TNT).

Example Sentence: That guy was giving me so much TNT last night!
by sanfran13 April 3, 2013
Get the Turtle Neck Tension(TNT) mug.