Finally a guy to "go down on her" but that was it? I'd lay down and let her ride my face lapping all her juices up. Then have her move a few inches the other direction and have her ride my face while i lick her asshole clean as well
Fat and ugly girls don't need to worry , there are always erected cocks and well filled balls in the neighbourhood , only looking for a cunt or ass to release their ejaculate.