What is Lmaomutefail?
1.
When a call centre staff member fails to hit the mute button on their telephone and obscenely berates the customer, inadvertantly allowing the customer to hear them.
staff member 1: Aaagghhhhh, f.f.s. this dipshit won't s.t.f.u. talking and let me fix his goddamn problem!!
customer: I heard that - who's your manager?
staff member 1: err, sorry sir.
staff member 2: LMAOMUTEFAIL
See