It's rude to give ultimatums.
Rin is bothered by the cigarette smoke scent which is from her partner smoking.
Rin wants to convince her partner to quit.
Rin approaches her partner with a gentle stance highlighting the health implications.
Rin makes her partner choose to either be with her and quit or she will leave him.
Rin's partner is encouraged to quit because of her support and kindness.
Rin's partner struggles even more to quit due to the additional stress.