That honestly a Kakeru problem then, a lack of emotional stability and healthy attachment patterns on his part. Yudai was only doing what would come naturally to anyone in their situation, given the difference between the two relationships, a close friend (confused misplaced sexual curiosity notwithstanding) and a sexual interest. Compiled with the big gap in urgency between the two situations, reconciling with a friend that you may have offended is obviously a much bigger priority that going to look at some painting of a sexual interest's that you can do anytime at leisure. Anyone who doesn't understand such a basic thing is the problem, not the other way around.
Girl I wrote this 5 years ago, but sure if you see the relationship as purely sexual interest then yes sure.
No one mentioned how he didn't see the painting before because he preferred to go to Ryo which was what set kakeru into his sad state.
felt like a lot of things were missing, Yudai got away with it easy.