The dangers of having a narcissistic love one in your life are dramatically portrayed in Coastlines. Be it a relative or a close friend, having a totally self absorbs person close to you (or your family) can be devastating beyond belief. Sonny's exploitation of Dave and Ann's relationship problems for his own gain coupled with zero sense of how destructive his actions will be to Dave, Ann and the children clearly show how "having" the wrong people around you or your family can ruin your lifes. The movie did a great job portraying this. Dave's decision to bring a "bad apple" like Sonny into his family was a dangerous decision that he even repeats at the end of the movie. Having sex over and over and over with Sonny showed Ann's desperation to escape the sacrifices of being a good parent and spouse. Leaving the "real' life one is in for a criminal with sweet talk and looks demonstrated how short sighted Ann really was. With hotter and more involved sex scenes and a better ending (maybe one where Dave forgives Sonny but has Sonny leave town forever) would have made this movie more enjoyable to watch and more believable. Bringing your best friend who's life is a mess and is banging your wife back home with open arms is not believable. Nice try but came up short in believability.
