What else do they have in common? I have 2 sims I use randomly (depending on my game scenario) that have similar traits and compatible signs. They both go bonkers about procreating.
Male: virtuoso; artistic, paty animal, family oriented, flirty
female: virtuoso, artistic, perfectionist, charismatic, flirty.
Even though he is "family oriented", it is often the female with the wish for children.