Co-Worker Grinding My Mother And Wants to be a Step-Father

My father was the area Don who raped my mother when she was young.

He was shot and killed by other gunmen so I hardly knew the guy.

My mother inherited a lot of assets from him of which no one up to this day knows about.

She open a auto body shop business and recruit young men from the area to work under her management.

Business is going very good for her where she was able to buy a house, cash and move from the ghetto to the hills.

She was always taking on new guy workers so she ask if any of my friends needed work as guys from the ghetto were living to close to work and finds comfort in being lazy.

I manage to round up a few of them from another community and things were getting back to how we first started out.

There is this one friend who my mother can count on to get the job done and at times my mother would often leave me or him in charge of the others.

Recently I notice my mother is spending most of the time on the road! 
I know she is a busy woman but what raise my concern is that my friend will most time accompany her and whenever they leave they came back with nothing.

I left for work one day and forgotten something, upon my return I found my friend in the house.

Same time my mother came out and the reaction on her face tell me they were having sex.

I have no problem with my mother happiness but I feel awkward having him in the house and being around him at work. I love my mother but this relationship gots to go.