that depends on so many things dude...if you try to have sex the next day with the old lady it takes some time...and even sometimes is impossible. But if for any reason I walk to my living room and find a penthouse pet seated naked and mastubating, I could fuck her probably 5-6 times the same day. And the wood will pop instantly. On the other hand, after let's say 3-5 days, the wood is up in less than one minute with the old lady.
I insist; humans ARE NOT animals of one sexual partner; that was forced into society by religion.