When he comes inside you and you feel it in the stomach really warm what does that mean?

It means you have...: That means you have a warm tummy, which doesn't actually mean anything. But it sure sounds better than feeling a cold stomach after a guy ejaculates inside of you. So, no worries... other than the usual forethought as to either getting pregnant or not getting pregnant, plus the usual thoughts of whether or not there is any STD infection risk with the sexual activity.