Because you're fat, and he's thin, and you're both _ #$*!ing_ugly.
I love that scene and just as much as the movie itself.
-You don't know what you got 'til you lose it.-
i loved the bit were there talking about personalities and him of corrie says well there not going to be looking at out personalities and the fat one says 'good because your basically a B@stard'
"Come out to the coast, we'll get together, have a few laughs."
Similarly I loved(also from the scene where they're tanning in Gerald's house) where Dave says "I mean what if, next friday, 400 women turn round and say he's too fat, he's too old and he's a pidgeon chested little tosser" and of course the later line "Anti-wrinkle cream there may be but anti-fat bast*rd cream there is not"
Classic.