Complex sentence: Vivian (Colleen Camp), a friend of Karen's, stops by to see if Evan needs help, but Genesis comes up to Evan, but after she goes back inside, Vivian angrily leaves, thinking that Evan is cheating on Karen.
Split into simpler sentences: Vivian (Colleen Camp), a friend of Karen's, stops by to see if Evan needs help. Seeing Genesis, Vivian angrily leaves, thinking that Evan is cheating on Karen.