A paunch in that area is normal. Can't say I've seen it in two distinct lumps, though. Cats (all animals) can get lipomas (fatty tumors). These are harmless fatty growths that are non-cancerous. They are usually left alone unless they begin to cause indirectly related problems.
But males DO have a mammary chain, just as females do. And they can get mammary cancer like females. Generally, mammary tumors feel harder than lipomas.
Males can (rarely) get mastitis or infections of the nipples themselves. One of my males' nipples became impacted and the area developed a pea-sized growth underneath. The vet drained the infection and put him on an antibiotic and he was fine.
There are hormonal imbalances that can cause the growth of mammary tissue, but it's rare, especially in neutered cats. Estrogen-containing drugs (like Ovaban/Ovarid), which are sometimes used to prevent spraying, or to relieve auto immune problems in males, make it more likely.
I'm sure there are a billion other possibilities. You should have a vet take a look to rule out any possible health problems.
