If I ask my GF to come to Sosua to meet me there is no issue. Her parents know and trust me. If she were to tell her parents that she was going alone or with another girl/prima they would "lock her up"
It's all about perspective and perception.
Of course essentially "every" Dominican I've ever talked to about this knows full well what Sosua is know for...putas... but it's also know as a great place to visit with an awesome beach and many good/great restaurants and acceptable hotels.
Tons of Santiaguero own vacation homes/condos/apartments in and around Sosua and tons more come Sundays, holidays. etc...