I don't really think there'd be any grounds for ejection tbh, I mean the Big Brother house is a television studio so technically having sex anywhere within it could be seen as public indecency
I just don't think they'd be able to broadcast it. In fact, I've often wondered why housemates go to so many lengths to try and be discreet when that actually draws more attention to themselves
if you're going to do anything, get the covers off for starters, but just find somewhere in the middle of the house. Sure, everyone will be watching, but I don't see any way in which they could put that on TV
I actually think Emma said the same thing on BOTS once too