Sounds like he's just not ready. I know it stinks for you more diaper changes and more money on diapers.
To know if he's ready he should do some of the following
Be interested
Talk about it
Express interest in going on the potty
Waking up in the AM or from nap dry (that's a good time to let him try he would obviously really need to urinate)
I don't think bribing works I always hear how it doesn't and it did absolutely nothing for me, cheering and singing and being all happy didn't work either.LOL ....
When he is ready which may be closer to age 3 you can try putting cotton underpants on him and letting him feel uncomfortable and miserable for a short amt. of time or making him help with the accidents and cleaning up.
My daughter was very very stubborn, and she knew she had complete control over potty training. It was a huge power struggle and drove me nuts. I'm also a single parent and my daughter showed interest at 15mos. and starting using the potty then but wasn't fully trained til 2.5 years old. I've learned that pull up are waste of money and make it so amazingly comfortable for them to urinate in that they don't mind. What worked for me was I told her she couldn't go to preschool in the following months which was the truth she needed to be trained and I was potty training 2 other boys at the same time and it became very competative and huge deal at daycare. They would fight over who got to go first and push and shove to be first in line. I also put our potty chair outside on our patio when she going regularily because she would never make it inside and up the stairs to our only restroom. I'm sure it looked funny but my neighbors didn't care.
Potty training has been the most difficult thing I've had to deal with as a parent and I know what your going through. Just try and be patient and when you least expect it he'll be ready and trained.
You could just stop talking about for awhile and just drop it and then in a few weeks start out having races. Have a race to see who can get in the bathroom and wash their hands the fastest before dinner, do that for awhile and then out of the blue just blurt out who can go potty the fastest and just run in there and go to the bathroom he might be shocked and so excited to join in... My daughter is 5 and loves to still do that. If I even mention that I have to go she runs in there before I can blink and hogs up our only toliet on purpose. Oh well I can always wait.