Dad - Hey Weiner, fancy going to Alton Towers for the day?
Me - Uh YES!!!!
Dad - Great, seeing as it's a 3 hours drive there shall we stay over?
Me - Yeah, that's cool. I need to be back by 6 though, I'm seeing BF/bestie/going to the cinema.
Dad - No problem. Your Mum already told me. Listen, I'm too skint to get you your own room, will you be alright sharing one with me?
Me - Yes, but you snore, and fart, and you won't want to wear a onsie because old man body hair makes me boak. Can I have my own bed?
Dad - Too right you're having your own bed, you hair gets in my fave and you moan about my farting.
Me - Ok, fair enough. Wouldn't want my own room anyway in a place I don't know, makes me feel spooky! Anyway, can we go on Oblivion first?
Please forgive the poetic licence here, but I really don't see anything sinister at all if you dsd and DH get on well. And personally as a 17 year old as much as sharing with either my bio dad or dsdad filled me with shame because I was an awkward cow, I'd have hated staying in a room on my own (maybe because I've always been short and fat?)