General

I can't tell you what he's thinking, obviously, but maybe giving my perspective as a gainer can give you some insight. I love my changing body. Seeing growth and where it lands is exciting and interesting. My belly is so cuddly, I love holding it and playing with it. I love feeling the weight of it and how it jiggles. I also find I am getting more comfortable I my body and self image as I grow...like this is who I really am as opposed to what people/society expect.

So, will you now feel free to indulge with him? You clearly know he would like it.

Having been a gainer in the past I totally agree with chubbypup.
Seeing and feeling the changes is beyond awesome because of the way it feels.
I have always dreamed of having my guy want to experiment and gain weight.
Helping and feeding him would be icing on the cake for me.
I have always adored big guys because they are so soft and cuddly.

This sounds very similar to my wife and I. She was always a bigger girl and I love that about her. I just always looked at fat as being super comfortable, in addition to being sexy on women.

at one point in my life I just decided that I wanted to also be very comfortable, and just see what it was like. It has been three years now I've put on about a hundred pounds and loving it.

My wife has been very supportive of me and really likes the changes. Before I had a full-on six-pack and was very ripped, now I finally feel like who I was always supposed to be. if he is naturally thin, he'll have no problem going back if he doesn't like it or when he gets older and he should for health reasons.

One more thing.
I'm naturally skinny, gaining for me has been very difficult, it wasn't until I read the thread on the ease that gaining can happen with cream that it became tolerable.

If he'd like to get there without all the struggle. And can handle heavy whipping cream, I suggest looking into that.