What is your definition of love? Are you speaking of Scriptural love or are you speaking of attraction? If it is attraction, then falling in attraction is self explanatory. It is no different than a piece of rust being attracted to a magnet, and then once it is there, it is stuck to the magnet.

If you are speaking of Scriptural love, then that is a decision/choice/action, and you can choose that for/with anyone.

My advice would be not to just write it off. Paul tells us that unbelievers who naturally obey the commandments are more righteous than "believers" who do not (Romans 2). I would say find out why he is not a believer, and then give it some time to see if your influence brings him to faith in the Messiah.

To the contrary, if he is a hardcore believer in another religion, then you are at fault, and your irresponsible choice to pursue it from the beginning will have consequences.

His definition of love is different than humans. The Messiah likens love to obeying the commandments. One of the most satisfying experiences of a parent is when your child listens properly, and the same goes for our Father in New Jerusalem.

John 14:21
21 The one who has my commands and keeps them is the one who loves me. And the one who loves me will be loved by my Father. I also will love him and will reveal myself to him.”

This is why Christianity is destroyed for "lack of knowledge," because they are "leaning onto their own understanding," because the Messiah is not revealing Himself to them, because they are not keeping the commandments.

Matt 7
21 “Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but only the one who does the will of my Father in heaven. 22 On that day many will say to me, ‘Lord, Lord, didn’t we prophesy in your name, drive out demons in your name, and do many miracles in your name?’ 23 Then I will announce to them, ‘I never knew you. Depart from me, you who are LAWLESS."

Most people mistake true love with attraction. Love is an action, a choice. So technically true love is a truthful action, a truthful choice. The Messiah likens love to obeying the commandments. Obedience is an action, a choice. We all have good attributes, and not so good attributes, so the "true love/soulmate" imagination is misleading.