Complex sentence: In season 8, Ross has a relationship with Mona (Bonnie Somerville), who wants to move their relationship forward, but, since Ross is having issues, ends up breaking up with him for multiple reasons.
Split into simpler sentences: In season 8, Ross has a relationship with Mona (Bonnie Somerville), who wants to move their relationship forward. But since Ross is having issues, she ends up breaking up with him for multiple reasons.