Here's a M/F story idea I would be up for. It does involve age play and incest however unintentional.
You, the estranged daughter of a convicted criminal doing life for murder, have been corresponding with the man you know as your father. The twist however is, you've not revealed you're his grown daughter (18-19?) and he's never seen a photo or met you before. After a lively exchange of letters back and forth a conjugal visit is arranged. For all he knows you're just some sick twisted fan of his.
The visit is consummated, and your unsuspecting father lays into you mercilessly, given all the pent up sexual urges he's been forced to abstain from being locked up. Only during the 'after glow' of the rough sexual encounter does she reveal the truth.
Where things go after that could be worked out. Perhaps she helps arrange his escape?