Pua thought that between Kaipo forgetting they’re anniversary or kissing other girls, the forgetting is worst, she really liked roses. (6)
1. Modifying the gerund “forgetting,” “Kaipo” should be the possessive “Kaipo’s.”
2. “they’re” should be the possessive “their.”
3. The correlative conjunction should be “between. . . and. . . .”
4. The superlative “worst” should be the comparative “worse” because we’re comparing only two events.
5. We have a verb tense issue; make the entire sentence past or present tense.
6. The sentence is a run-on, sometimes referred to as a comma splice. Change the comma to a semi-colon, add a conjunction, or start a new sentence.
A corrected version might read
Pua thought that between Kaipo’s forgetting their anniversary and kissing other girls, the forgetting was worse; she really liked roses.