With skunk clowns, you can actually keep harems. They can be in small groups and do absolutely fine with each other. That is one of the coolest things about skunks.
But, to answer your question, "yes" you can put another skunk in their and they will most likely pair up. Skunks are pretty docile and will usually be accepting of a mate. Do watch closely to make sure no big battles break out, though.