Ok I've got to do it.

After 3 weeks Robert trapped in his sister in Law's body had given up on her ever giving him his body back.

Which meant he had no choice but to settle down into his new life of being his brother's wife which came with certain obligations like sex.

So unable to come up with any more excuses not to have sex with her husband his brother he decided to have one drink before going to bed and finding out how good his brother was in the sack and what sex was like for a woman.

Which after getting over the initial shock & repulsiveness of it thanks to the alcohol in his system he quite enjoyed himself which made him more comfortable with the situation he could not get out off.