I wouldn't be surprised if some of this goes on between SINGLE cast members, but actors are also professionals and I seriously doubt someone with a family and 4 kids (bakula) is going to screw around with a girl on the set.
Who was Phyllis Strong?
by the way, I dind't mean to tread on "shippy" territory, hehehe, I'm JUST sayin, if anybody's gettin it on, might as well be our TWO, right?
You just have to look at the Stargate set to see that people are gettin it on... Michael Shanks had a daughter with the Brazilian model that played Shar'e his wife, and then actually married and had a kid with the new doctor, Lexa Doig.