Here are a couple mods for you to help if you are tired of gay sims. I take no offence to peoples opinions even if they differ from my own. You have a right to your opinion. You also said you wished to not offend anybody. The thread is closed or I would have put the links in the thread. Here you go. For most Sims, they don't have a set preference. But these mods let you choose a preference for your Sims and play the premades long enough to set their preference too.
More CAS traits. This will allow you to flag whether your sim is straight or not.
Gender Preference Set This allows you to choose your Sims preference for being straight.