Trust Fuck can be interpreted in two ways.
the first way means that basically you trusted someone then they kinda screwed you over big time.
the second way is in the more literal sense as in when two people trust each other a lot and then they fuck.
"Oh my gosh i totally trusted you then you stole my f'ing laptop WHAT THE HELL"
"haha sucks for you, you just got trust fucked"
Jen: I really trust you
Bob: and i really trust you
lets trust fuck all night