It will make Roushk and Othra like you more and it will also allow you to activate the love scene of Ohtra or Rousk
You start a polyamorous relationship with both of them I think ... and if you ask yourself there are still no sex scenes with either of them but there is a very romantic scene if you ask to see the fireworks either with Othra, Roushk or both at the same time time (it all depends on who you chose as your romantic interest)