Can someone explain the joke on this very old postcard?

by and42is

So one thing led to another on Wikipedia, and I found myself reading about Donald McGill and his trial for 'saucy' postcards.

This card is linked as an example, but I don't get the joke.

Can someone explain what's supposed to be funny/saucy about this card?

intangible-tangerine

I think..

'Both ways' refers to an each way bet and in this context it's being used as double entrende to refer to two different sexual acts. Which those are is left to the imagination.

She's saying both 'my sweetheart gave me a pound to put an each way bet on' and 'my sweetheart gave me a pound to perform two different sexual acts'