My perspective may be skewed by the fact that I was raised by a mother who was pretty absent in the taking care of department but...

It seems to me that giving in and cleaning the mattress did nothing to change you son's view that it is women's work. I don't think that unconditional love means putting up with everything a child does or does not do. I think it means loving them while expecting and helping them to grow up and take care of themselves. He will indeed choose his own path, but loving him does not mean you have to go that way with him and hold him up the whole way.
And having read your comments about why you edited your first post, I don't think you are a nag, nor do you need to shut up. But maybe you need to spend a little more love and care on yourself. That might be the best example you can set for your son.