I think it will be revealed 100% to Kogahara that Lemon and Akiyoshi are body-swapping later into the story like with his friend. With that in mind imo there are 2 ways this is gonna go.
1st - She still decides that her love is real, since more and more moments with the real him have added onto the reason y she loves him, so the one moment with Lemon that started it all is now just what sparkled her interest, not why she loves him now.
2nd - She was already kinda losing a bit of interest in him, since it wasnt the "real" him she loved, but rather Lemons personality. Now that she knows the truth, she moves on from him, and Aki begins to like Lemon again through their day to day interactions. (I think this is the most likely outcome, since Lemon and him are most likely end game).
They better give a REALLY good reason why Lemon said that fukt up lie to him doe, otherwise itll kill this manga's rating.