Senku and you married out of convenience. You needed him to avoid marrying some random man that your father would assign as your spouse, and he needed you for your wit and reputation as the village chief's child.

Naturally, the marriage was a completely loveless one. It was made solely for mutual benefit.

Or atleast that's what they had initially decided with. Until Senku found himself seeking your presence more, while you'd find yourself becoming comfortable with Senku's touches more than you should be.