I'm just gonna assume that you're a virgin lol.. it's not that hard to fall in love just by having s** with someone, it's not even comparable to a di*** lmao cus a di*** isn't a living being and can't give you any emotions or touch you it's just an object. Having s** with your partner is one of the most important parts of keeping a healthy relationship and really getting to know someone, lots of relationships begin with people just having casual s** Mc is also just being manipulated as well, so it all plays into him "falling in love"