It seems Arnold Schwarzenegger, his Twins co-star Danny DeVito and director Ivan Reitman have all kept in touch over the years, and it seems Universal Pictures came to them with the idea. Here's what an insider had to say about the possible sequel.
"A Twins sequel. Knowing Arnold, Danny DeVito and Ivan Reitman are all still in touch and want to work together again, Universal came to them about it. It's a germ of an idea that could spread fast."
It doesn't seem that a writer is attached to this project as of yet, and it isn't known what this idea is that Universal came up with.
Triplets is in development and stars Arnold Schwarzenegger, Danny DeVito, Eddie Murphy.
Twins was released December 8th, 1988 and stars Arnold Schwarzenegger, Danny DeVito, Kelly Preston, Chloe Webb, Bonnie Bartlett, Trey Wilson, Marshall Bell, David Caruso. The film is directed by Ivan Reitman.