AITA for refusing to sign over my stepdaughter's college fund after my wife's affair?

My wife called her affair “healthy co-parenting,” told our friends I was basically only useful because I paid for her daughter, then tried to guilt me into signing over the college fund I had built for that same kid. I told her I was willing to sit down and talk. She thought that meant I had finally folded. I showed up with divorce papers and one account change she had never bothered to imagine. ---------------🌞Sunny Stories🌞--------------- #reddit #stories #redditstories