To be fair, they've technically been together from the start I just kept the posting about them separately; namely, Vivi (who isn't always fat but often is,) and Chris are a couple and I've drawn them together a few times. Ruby and Chris also know each other through vampire business, and there's mutual attraction there as well (this a horny as hell fetish setting so even with dedicated couples there's plenty of promiscuity. It's fine.)

I haven't fully fleshed out (haha) every interconnection between every character but there's generally a lot of admiration and lust between the two camps because they're mostly all hornt-up size freaks.