The idea that anyone could confuse him and Sebastian as brothers was just as funny to Bryant. Not that he wouldn't be against a dash of his friend's DNA in his own system -- no, good Lord, not like that. Rather than be frightened of or appalled by the unique creatures of The Red Door, Bryant was drawn to them, curious to know more. Sebastian had been no exception. Now they'd reached a place where Bryant could patch a tear in his friend's human skin and they could both enjoy a cup of tea afterward.
It was just as funny that Rachel would jest that Bryant was Sebastian's skeleton. The tensile strength of skin is considerable, given its moisture content, but stretching Sebastian's skin over his larger frame would be the height of futility (just the same, Bryant filed the idea away for the next time Sebastian was ready to fully regenerate an entire skin; perhaps the surgeon could repair the old one and keep it viable long enough to run comprehensive tests).
Because he was among friends -- because Sebastian had assured Bryant he was invited, because Rachel said it was always good to see him -- the good doctor felt it was all right to laugh along with their comments. And he was pleased with himself for guessing the costume correctly. Blade Runner was one of a handful of films, books, and other media that Bryant considered real possibilities for the future. Synthetic humans? Was it really so far-fetched from shedding your skin, regenerating, fashioning limbs (however unwanted)? Besides, there'd been a Bryant in the film, too, though this particular fellow had been secretly cheering the replicants on.
It was an understandable thing, to want to come home, to want to live.
To say all of that here and now wouldn't have been out of character for Bryant but he'd simply ducked his head again a little shyly at Rachel's smile. Smiles seemed so simple when other people utilized them. "It does," Bryant assured her, lifting his head to get another good look at her hair. "It r-really helps you t-to look like Rachel, Rachel." There was earnestness in his voice; he didn't even get that he'd said something potentially funny. Human interaction was a bit hit and miss with Bryant.
If there was one thing he possessed, though, it was manners. When Rachel brought up the idea of drinks, Bryant enthusiastically agreed and added, "Oh, do let me stand you all a-a... a round." He wouldn't drink alcohol himself at the moment but he did recognize that it was acceptable and indeed possibly expected in a party atmosphere. "I'll pop over to... to the bar. What would you like?" he asked, looking from Rachel to Sebastian and back again.