Wow, that's the loudest 'no' Tony's ever heard from somebody saying 'yes.'

"I'll come find you after I've got my dad set up. We can grab some dessert from the fridge and go up to our room and... talk this out. Figure out what we're gonna do."

He makes very sure to say 'our room' - he doesn't want Gene getting it into his head to grab all his stuff and move out while Tony's out with Howard. He doesn't want Gene to leave. Not permanently. Worst case scenario, he has to crash somewhere else for a while until Tony can find the courage to break it to his dad that they're together.