I don't see what the big deal is, this has been happening since TS2. I've had sims who were naturally attracted to the same sex, and I just roll with it. I don't control my sims THAT much. I watch them when they are in groups and I see who they are building up a relationship with the quickest, which usually means there is also an attraction there. When they added the Turn on/off system in TS2, I had sims falling for the same sex all the time just based on those attractors. I never knew Summer was a lesbian though, she's not at all aggressive in my game (if she's still alive. last time I saw her she was an elderly cook at a restaurant).