Slow Responsed

To deliberately respond slowly to an instant message conversation online in an attempt to frustrate, annoy, or make the co-respondent jealous by appearing to be juggling many conversations at the same time or to project the impression of being too busy to reply in a timely manner. This is typically achieved by putting one's phone down and performing other tasks knowing full well the other party to the conversation is hanging on waiting for an immediate reply, and that aforementioned person is edging towards homicidal thoughts towards the instigator.

"I was having a WhatsApp conversation with Mary last night and she slow responsed me throughout the conversation"
"Oh man - that's unforgivable. Ditch the bitch"