If my baby spits up and then acts hungry should I feed him again since he's empty now? Or is acting…

If my baby spits up and then acts hungry should I feed him again since he's empty now? Or is acting hungry a sign of discomfort and not a good idea to feed since he just spit up?

Also can breast milk be re frozen after being defrosted once already if it hasn't been used or anything? Just to change what it's being stored in