I too have accidentally gained weight while encouraging and trying to Fatten my wife. After I noticed 10-15 Lbs of unintentional weight gain I decided to Intentionally gain. At first I was excited and enticed by noticing the ever increasing size of my Belly....and then I was aggressively disciplined into seeing how big and Fat I could get....but most of the arousal came from trying to get my wife to comment on my weight gain or tease me.
Eventually I became consumed with over feeding myself and that became arousing in itself....until I discovered that my eating was out of control and I couldn't stop eating huge amounts of food which became even more arousing.
I guess as time goes on as an FA and very into weight gain....it goes in many more directions. At first I liked chubbier girls and them gaining weight, then it was heavier girl/woman gaining weight, now I love women 300+ lbs. gaining weight, I get aroused on watching my wives eat and her appetite increase, love to see my wife gain weight and ultimately would love to have a mutual Gaining relationship and even fanticize about both of us being over 300 Lbs. and being a huge Fat couple.
So....roles with this fetish take shape in different areas as it goes on....
9 years