Why doesn't he want them to meet?? Tf??

dowon confessed to taeju when they were in high school but dowon got rejected. dojin is just feeling insecure since all this time, he has been competing with his brother for taeju even though dowon and taeju have no connection anymore. remember how taeju referred to dojin as "dowon's little brother" so back then, in dojin's mind, dowon is a much more significant person than he is. that's all in the past now but dojin is just a silly little boy haha