Tactical text

A text message that is sent- usually as quickly as possible- in a situation when one should not be texting or at an otherwise inconvenient or risky time; hence the need for the text to be sent in a tactical manner. For example, during school when phones are not allowed, during a movie at the theater or when playing a video game that cannot be paused (like an online game).

"Sorry for going AFK for a bit, I had to send a tactical text"
"Bro, I was tactical texting her the whole time Mr. Davis was lecturing, and he didn't suspect a thing"