Around 18 minutes into Shotgun, Maika Monroe is in some lingerie talking dirty as part of someone’s fantasy. The top part of Maika’s bodysuit is somewhat sheer and you can make out her areola. Or it could be pasties. There are also lots of scenes with Maika in her bra, and a scene around 48 minutes in where you see a tiny bit of Maika’s ass from the side as she is having sex.
Near the beginning of the movie, an unnamed actress shows her breasts briefly during a sex scene. Looking at IMDb, that actress is likely Jordan Monaghan. There are also some random naked strippers about an hour in.
Shotgun is currently playing at SXSW.