Recently a co-worker of mine quit because of various reasons, mostly I would say he had himself to blame...before he left, apparently he had stopped working on his stuff and a month ago, my supervisor called me and said she was going to move me to that department as It as way behind and I basically had to catch up all his work that he had left behind and was not doing, in the process of my own job in the new department piling up. 

I used to work with his mom in the previous department and had a tough time dealing with her as well. She threw me under the bus many a times in the last 3 years. 

So I welcomed the move and yesterday out of the blue he texted me asking me to be his reference for future jobs. 

I do understand that a employment reference phone call from his future prospective boss may just be a employment verification or more than that. I do not know and I didnt want to take a chance. 

That put me in a bind. I know the type of person he is and the type of work ethics he has and I didnt feel comfortable saying yes. 

He basically doesn't keep in touch unless he has something he needs and when I texted him my refusal with a note saying that I will look out for any opportunity that might come up for him - he didn't reply back. 

I am wondering if someone has gone through a situation like this? How did they handle it?

I have trouble saying NO to people - even though i have heard more NOs from other people in my life! I have no animosity against him and don't want to jeopardize his future either. Even though that might not be the scenario. 

Thanks