Shortened Polish male names

Hi. My polish manager has told me to use a different form of his name (Bartłomiej) when we are speaking. I know the usual shortened form is Bartek, english speakers and other colleagues use Bart, but he wants me to use a name sounding like Bartus or Bartush (sorry but I don't know the correct spelling). What is the significance of this name?

Bartuś is diminutive of Bartek. Rather reserved for children 5 and under, or among adults after 12 or more shots.

It is probably Bartosz that he wants you to use. (Bartosh)

He did say it is a friendlier or nicer version than the other diminutives of his name.

He has also started to call me lady when he greets me. Is there any meaning to this?

What do you want it to mean?
Since he is your manager I would assume he likes you and thinks you would make a sweet personal friend..? So is allowing a closer warmer form of address not encouraged with everyone.

"Lady" in English? Just "hey lady" or with your name?

but maybe he LIKE YOU likes you..... ^_^

With English, my guy often calls me m'lady. I started catching on when that and "baby" started creeping in as diminutives that maybe I was not just a "buddy" anymore :) My guy can't have any shorter a name

We have met for coffee on one occasion outside of work. And plan to again in the next few days

He has started saying 'hey lady' when he sees me for the first time each day, and has took to shortening my name also, even though I don't introduce myself using this.

But as for the relationship, I want to figure out first if he is just looking a friend, or if how he refers to me means he wants something more.

definitely :-)

At least I would if I'd ask anyone to call me like that.

Cinek