Condoms! Important. You should use them. Bet they're swell. (Well, I wouldn't know, I have a skin sensitivity to latex, but I bet they're great nonetheless). Anyways, here's three recolours of Nixy's anti-sprog protection so your sims can get it on without worrying about any lasting, unintended results.
You get three boxes of condoms, listed here:
Trojan Sensitivity Pack
Download here! Meshes included.