For example here is what goes through an INTP mind. OK she keeps on telling me she loves me, I don't respond that I love her for how many months?, She keeps on asking me do I love her? I say I don't know how I feel, I don't think so, she sends letters emails expressing love I see her telling other people she loves them, she always talks about things she loves to do, loves to eat. She wants some validation so she feels better. Ok I will respond a email with "luv Spamtar".
Rationalization: Ok according to C.S. Lewis there are 4 kinds of love:
storge,philia,eros, and agap?. I feel affection, friendship, sexual bonding, and love of you as one of God's creatures.
Ok either one or more of the loves apply or a combination thereof...OK since you forced me I "luv" you. Now please don't ask again.
Chances are that he may or may not be in love with you. You will not know for sure unless you leave him and monitor his reaction. The only downside is that the INTP has a lot of pride and even if they do love you they may shun you if they think you abandoned them.
I have been "in love" only once. But I have loved many women and show my love through my actions to them.