What happens to your mum tum when you get pregnant again?

Okay so I'm aware this might be a stupid question but I'm going to ask it anyway so no hate please 😂

I still have a bit of a 'mum tum', y'know that little pouch at the bottom 😭 from having my little boy 2 years ago and I was thinking of ttc number 2 soonish. What happens when you get your second baby bump? Does it just kinda stretch out into a cute bump again or does it stay saggy? Just trying to see if I need to get super fit or not first 😂 thanks!