Dad And Son, Hopefully

He's staying with us for another fortnight, this after already being here three weeks.
His home was effected by a house fire next door, so my boyfriend's father is now sleeping in our guest bedroom.
Only my boyfriend M hasn't been the only one fucking me since he moved in temporarily.
I work from home, Gary is semi retired and his son works at our general hospital on a night shift rotation.
Gary said no at first when I offered him a blow job. But changed his mind when I walked into the lounge naked. I already knew he'd fucked guys before, so I chanced it that my boyfriend's dad would want a younger man's hole to fuck.
I'm not kidding you, Gary can fuck for England.
His son M has a similar sized cock, but Gary's is thicker and my boyfriend's dad can fuck all night. Where as his son once he's cum, it's all over.
Gary has said no to us having a threesome. And indeed told me not to tell his son I've taken his cock up my down my throat and up my arsehole many times now.
But I couldn't resist yesterday afternoon saying something as Gary's son fucked me in the shower.
I let him know his father had fucked me in the same position the night before.
It had M fucking me much harder and had him whispering in my ear, he'd loved to have watched.
I've suggested to my boyfriend that we have sex in front of his father tomorrow afternoon and see if he'll join in.
Gary's son was more than up for it, but we'll have to see if his father will be.