REINGELEGT. Brazenly nailed through on the public beach!

I finally wanted to relax a bit and went on holiday with a girlfriend. She put some cream on my back and then went to the hotel. When a guy approached me and asked me if this was an offer? I really didn't know what he wanted from me until he told me that it said "FUCK" on my back. As soon as I could say something he grabbed me and pushed his fingering into my cunt and fucked me right on the beach. We also had enough spectators and one guy watched us and even almost wanked me. Boar was that cheeky but what should I have done? Would you have insisted on my offer?