double chat 

to use two (or more) instant message services to chat with one person.

"Glenn and Audrey were both double chatting with me last night through AIM, Google chat, and Facebook chat, and it got really annoying."

double chat by Nate K April 16, 2008

double chatting 

trying to keep up with two chat conversations at once, sometimes falling behind in one or forgetting to talk to one person

hey, sorry i replied late, i was double chatting.

double chatting by A Friend Of Tyler Durden November 20, 2009