We really can't judge what's necessarily right, wrong or what's socially acceptable in these celebrity and highly notorious individuals lives.
Jamie Foxx said in an interview one time where he had models playing volley ball topless at his house with a bunch of people.
I'm in no way condoning Trey Songz's actions but that shyt is a whole different world that we won't ever understand.
I've had a female friend told me after a Da Baby concert his security was going around asking girls if they want to go to like an after party. They sent a text message out to everyone that if you aren't willing to fukk and suck then don't come.
It's honestly a world we can't even fathom being regular folk living regular lives.
The difference in those two cases is probably expectations, though.
In the Jamie Foxx story, there's a chance that he told the models up front what type of party it was, and they had their chance to decide if they were going or not.
In your story about Da Baby, that was probably the smartest thing he could've done. They have text message proof that he, or at least someone speaking on his behalf, established that if they were going to show up, they were at least initially accepting the possibility of sex. It'd be a whole different thing if he invited them over under the guise of just kicking it, and then tried to run through them under the assumption that they knew he was inviting them over to get ran through. shyt, even then, if shyt gets a little too out of hand for them once they show up, they can still say they're not good with it any more, and deserve their opportunity to be left alone, or leave.
In general, most women aren't signing off on some guy popping a breast out for everybody to see, even if they were completely fine with the guy they came over to see seeing it privately/discreetly, or even getting handsy with them on the low.