Gladiolus Amicitia history of Flirting with multiple women.

⁣It started at Chapter 3 Sidequest redfrogs.

And the rest of the sidequests.
Afterward, Ignis Scientia ponders where he has heard of her, and recognizes her surname, as Sania's parents are likewise renowned scientists. He does seems to care about her too. If you ponder someone over and over again without even knowing it. They care about that person. Whether you believe it or not. Facts don't care about your feelings.
Link: https://finalfantasy.fandom.com/wiki/Sania_Yeagre

Link: Rainbow frogs - https://youtu.be/gBsNDITdGzs

Link: https://youtu.be/KGnfzpWFZcw

Link: Yellow frogs - https://youtu.be/k9P9xa_BRVo

Link: https://youtu.be/9wpL3Jr1s3M