The reason to push there is if you think you can take the pot without seeing any more cards. But the $5 raise means you may get a call, so I would simply call that bet or reraise to $10, to isolate. The raiser may be semi-bluffing with AXs so a reraise will probably isolate to the two of you, giving you a big advantage on the draw. From that point on, you want to play it slow if the flush hits.