'Leaving Clegg in charge' is a phrase that refers to something that seems like a good idea at the time but ultimately ends in chaos, usually referring to leaving someone in charge who is an incompetent idiot.
David: hmm I feel like a very expensive holiday to Italy, Nick you're in charge for the week.
Nick: Oh thank you David, I won't let you down.
*Comes back a week later to riots and madness*
David: WTF
Boris: That's what we get for Leaving Clegg in charge.
Leaving you on read means that I don't want to talk to u atm. This means it's the end of the conversation, not "keep texting me until I eventually respond"
A: mhm B: *leaves on read*
This indicates that person B is done talking. This does not mean person A should keep talking. Leaving someone on read means to leave the conversation.