It's basically a way of exagerating the point so people know you really mean what you are saying. See example 1.
It can also be used as a sarcastic response. See example 2.
"Oi you, Did you shag my mum last night?".
"YEAH!!!,WITH BELLS ON!!".
"Oi you, did you file those reports I asked you to do?".
"YEAH, WITH BELLS ON...NOW SUCK MY CHODE!!!".
Ready to go full tilt. Possibly early version of balls out.
Poo: You coming to my party?
Roo: Yes, I will be there with bells on.
To arrive triumphantly. In the days of delivering freight by horse or mule drawn wagons, the teamsters would often festoon their rigs with ornate bells. If they became stuck or otherwise needed help from another teamster, they had to "pay" the one helping them get out of trouble by giving him or her some of their bells. Therefore, if you arrived at your destination without the help of anyone else, and perhaps even gave aid along the way, you arrived "with bells on."
He was shot at twice and missed once, nearly drownded crossing the crik, lost two horses and had to replace a wheel, but he needed no help and arrived with all his freight and WITH BELLS ON.
"with bells on" was first used in the Royal Navy and is in referance to a sailors bell bottom torusers. The uniform that included these trousers was their dress gear and was only worn when on liberty or various ceremonies like colours or sunset. It was also popular to wear this uniform to events such as weddings or funerals as it was proberbly the best clothing they possessed.
So to say u will be somewhere "with bells on" is to say u will be in your best dress and in a military fashion.
Used to add oomph
to any phrase to simply reinforce your point.
Terence: "Fuck off Harry, with bells on."
Maureen: "Yeah that hurts like fuck, with bells on."