My girlfriend wants me to gain weight?

[Katha28.12]

Okay so a little bit of background here:

My girlfriend and I have been together for about 4 months now, she's not only my first girlfriend but my first relationship ever. She's also a few years older than me and so is the experienced in our relationship. On the first night we met we immediately became a couple, which was I was amazed at, since she's everything I have ever wanted in a girlfriend. She's taller than me, about 165 cm and weighs around 55 kg, she eats healthy food and works out a lot, goes swimming, biking, hiking etc and she works as an ICU nurse so she is constantly on her feet and really fit. She has tattoos and piercings and that kind of hippie chill vibe to her.

I myself am slightly overweight at 153cm and balancing at 62/63kg. I have spent most of my life being super self conscious about my looks, I have a tendency to overeat when I'm stressed and in years when school got harder and the added stress of figuring out my sexuality has made me gain a lot of weight. 

In the beginning of our relationship it never struck me as odd that she liked to give me belly rubs and put her hands on top of it when we were watching TV. In the bedroom, she would kiss and stroke my belly too which surprisingly really turned me on and I loved it. She would sometimes buy me large meals or cook for me at home and always loved to rub my belly when it was tight and swollen, but I still had zero suspicions.

Last week she came out to me about her preferences. She said that she really likes girls with a belly and just a little extra weight on them, and then she asked me if I would be open to even gaining a little weight. At first I was shocked and a little upset because I just felt like a checked off criteria box. But she reassured me that she loves my body exactly the way it is, and that if I chose not gain weight or even lose weight she would not love me any less.

I'm still quite unsure. The idea does excite me a little and I actually like having my belly played with but then there's this part of me that fills up with dread at the idea of getting fatter and I'm just so torn! What should I do? Should I give gaining a try?

[Katha28.12]

Thanks for the advice. I'm still thinking about it but I'm leaning more into the experimental option. Maybe I'll gain like 2-3 kilos and see where that leads. 

[Katha28.12]

So a little update for those interested:
I've decided I would give gaining a try.
My girlfriend and I had a long talk about it, I expressed my concerns about body confidence and feeling ashamed of what other people might think of me, and that I wouldn't cross the 75 kg barrier. She was totally fine with that and just told me she was looking forward to supporting me and seeing the changes in my body.
So I've just been letting myself go a little with snacking and eating bigger meals and it's already showing. My belly is plumper, my arms, legs and butt are getting jigglier, and I feel softer all around. I can't really believe it but for the first time I'm actually starting to like my body!
My girlfriend is definitely enjoying the weight gain as well. She always tells me how hot she finds it that I've gained weight, and things in the bedroom are better than ever. When I wear tight pants she likes to fondle my muffin top and sometimes when I lay in her lap she likes to rub her fingers under the bulge over my pants.
My weight on sunday was 70 kg. It's going crazy fast. I'm becoming more comfortable with having my rolls played with and my belly more involved in our sex life.
I'm excited to see what the future holds, I don't know exactly what's coming next, all I know is that I'm going to enjoy myself all the way!