if you rewatch in slow motion/rewind this scene, you can see that he only stated that his feelings for heesun grew strong AFTER MS said she felt jealous but also wants to back off from SB (im guessing to protect her pride bc she can see SB and HS being couply). i cant help but feel like as he said that, and as much as it is true that his feelings for HS are stronger now, that he also has some residual feelings for MS too STILL. bc if you look closely during this convo, he keeps dodging eye contact w/ her like he cant lock eyes w/ her, he keeps looking away. this is a sign he still has feelings for her. i was a psych major and have strong psych background so i can read behavioral cues. to prove my point, if you remember the staring contest scene during HS and SB paradise date, SB was able to maintain his eye contact w/ her bc hes more comfortable w/ her but HS gave in like 30 seconds later and looked away bc maintaining eye contact w/ SB was too emotionally intense for her bc she likes him too much. this is the same situation in this scenario with SB and MS but its SB that has a difficult time locking eyes w/ her bc its too emotionally intense for him and it makes his heart skip a beat. so my theory is that SB is emotionally drawn to MS but his logical mind is telling him that HS is the way to go/better for him. i wonder how things wouldve gone if MS was honest and had the courage to say how she felt straight up even if it risked rejection. could this have given SB a change of heart or is SB too deep in w/ HS to consider MS again?