I totally agree with the comment about the guy has to ask !
One of my favourite revelations from Beth's past is from a time she went on holiday to a Greek island with a guy she had been seeing for a few months. Apparently up until that point they'd been having good but relatively straightforward sex. Lots of it but nothing too crazy.
When they got on holiday the regular and fun sex continued - including sex on a beach (but I'll get distracted!) - and then one afternoon he simply said how he'd enjoyed anal sex with previous gf's and he'd like to do it with Beth.
In my experience girls will generally want to do something to please bf's in those situations and no girl likes to think that his ex was more fun in bed than she is....therefore he and Beth spent the afternoon in bed with him fucking her gently in the bum. By her own admission she loved how naughty and sl*tty it felt and had a great time. The rest of the holiday was in her words ' just a week of fucking in pussy and bum where she couldn't stop cumming for him'
However, and this is why women are so fantastically impossible to work out - she dumped him about 2 weeks after the holiday!
anyway, I loved her telling me about a time she felt sl*tty and it was made even better by the fact she'd clearly had great sex for a week and got a suntan!