If she likes you grabbing her belly during sex, just play that up for now. I think the gold standard is always just being open and honest, but gently incentivizing being bigger via pleasure couldn't hurt. If she's into it, focus on the belly or other fatty areas a bit and just let her know you'd like her bigger. If she's cool with it, great, if not, it's her body. Chances are if she's already gained 40lbs unintentionally, she'll gain more anyway
3 years