When you are thinking of purchasing additional equipment, instead of purchasing additional lenses, I would strongly recommend instead buying a dedicated flash (a flashgun aka speedlight flash). The built-in flash itself is contributing to images not appearing "soft," (the bright highlights directly on the subjects, the shadows behind the couple). Unlike the built-in which always illuminates straight on, you can bounce an external flash, which lights your subjects in a way that looks more like natural light. This specific lighting issue can be corrected somewhat digitally, but it is much easier to prevent. (I promise you, getting an external flash made more of a positive improvement to my photos than any lens ever has).