I don’t know which one, but one of the meforshim explain it to be a natural phenomenon, and yes, an automatic reaction, feeling. But the love must be sincere and obvious, then it will work both ways.
That’s what one Pirush (I think it’s Rabbeinu Bachaya) says by “VaYigash Eilov Yehuda”- Yehuda tried to come close to Yosef, stratigically, by gushing forth love upon the viceroy of Mitzraim, as a desperate attempt to save his brothers from their predicament. This way Yosef will be “forced” to love him back!