As if Youmu's flat chest and "flow"(the way her body just seems to curve from shoulder to ankle) weren't seductive enough, I think I'd probably lose control over her doing just that. :/
Artists should really spend some extra time in health classes.
You know, when girl hold a PACKED condom in mouth, it's an invitation symbol, can be understood by every man in the world. So it's pretty userful in erotic, but not porn arts...
I think, doing this without ripping the condom is quite easy, the hard part would be going all the way down the penis. So if your GF can do this, give her some sort of praise