I'm going to buck the trend of AWWWW and say ... that MOM is cute. The smile she gave on page 16 was ... OOOHWEE ... she could get it.
On a more topical note ... of course she did NOT see his picture of when he was young in his room. That would resolve the plot too quickly. We have to go through 200 chapters of drama, catching feelings, cock-blocking chicken-cubeing, and Kawai doki doki before we get to that point. Also, I know the author is going to do their darndest to make the lesbian a somehow viable love-interest option. Please don't.