Subtle hints will be almost completely useless on an INTj, because even if we happen to notice the hint, we'll doubt and second guess ourselves about what the hint was supposed to mean, and just become unsure of what to do. You have to be very straightforward and open about what you want to say.
And yes, INTjs really do want to be "smothered", especially by ESFjs. We can feel very vulnerable in social situations, and can get very uncomfortable when people get too close. People notice this, and tend to keep their distance from us. People rarely hug INTjs, for example. Deep down, what we really want is someone who won't be deterred by our uncomfortable exterior, and will keep trying to get close to us, and make us feel comfortable enough that we can finally relax.
Anyway, assuming this guy really is an INTj, I wouldn't worry too much about how he'll respond. Even if it turns out that he doesn't feel the same way, he'll be flattered that you like him, and be very nice and understanding about it. It's worth the risk. When you're 92 and looking back on your life, you're not going to regret telling him how you feel -- but you definitely would
regret it if you never said anything.