Maybe the OP misinterpreted the advert.
If you want to fuck her it's £110.
If you want to get fucked it's £80. He got fucked, just she didn't use a strap-on to do it.
Joking apart the advert headline is £80hour instead of the usual "Munter Eva seeks your wallet, no services available" then the ad states it's £110. Just another warning sign to add to the many already there. As if the pics weren't enough.