Aye, had one like that who nearly broke a good band up.
We were a 7-piece funk band, two girl singers, and us guys made it a rule not to get involved with them, for obvious reasons. So what does the guitarist do? Pulls one of them (on the sly) and they begin a clandestine affair which eventually manifests itself as a schism between them and us. They take to arriving, late, together and leaving in silence. They also quit socialising with the rest of the band and eventually, after a few weeks as an item, split.