Problem: How does the sentence end?

Nick thought that parents just don't understand but Ryan thought that they did understand.
Answer: Nick had a contentious relationship with their parents.

Problem: How does the sentence end?

Kenneth asked Jason for some tips on growing the perfect mustache, but
Answer: Jason had never had one before.

Problem: How does the sentence end?

At the Halloween party, Robert got second in the costume contest won by his enemy Leslie which really made
Answer: Robert mad.

Problem: How does the sentence end?

Natalie spent a lot of time brushing their hair but it only took Patricia two minutes, since
Answer:
Natalie had extremely long hair.