Having had sex for years with someone who had two (plus a didelphic uterus -- two compete uteruses), it sounds exotic and alluring -- but I can assure you that beyond the initial discovery it doesn't make that much difference. Once you're in one, you're in, and you're unaware of the other.
She preferred using the one on the right (the left was smaller, less comfortable). So the only difference was the occasional alert that "you're in the wrong one." Then you just back up, take the other fork in the road, and continue on.