One way to be sure he stops liking you is to become an insecure nag who demands the right to control his actions.
When folks start smothering their significant others, those others, not knowing how much worse it might get, start looking for a fire escape.
You have an insecurity, but surveilling your BF is not going to make you feel any better. When we search for reasons to doubt, to suspect, we can always find them.
Try growing up a little and understanding that only one of two things is going to happen:
Either you will grow closer, and more trusting of each other, and be together.
Or one or both of you will drift away or lose interest or meet someone you want to be with more.
That is it. Just two options that are ALWAYS present in EVERY relationship. No matter how long you are together, it might yet end.
So relax... why are you together at all in the first place? Is it not to enjoy one another, accept one another and support one another?
If you want it to last, then focus on those aspects... make sure you enjoy that time together and do not throw it away with ill feeling, suspicions and demands.
That is the one path that is most likely to keep you happy with each other.
And do not borrow trouble by imagining and suffering over something that has not happened yet, and may not.
If you focus on acceptance and loving, if you know you made the most of every hour together... then if it ever comes to an end, you can walk away clean, knowing you did your best and that that time was not wasted.
Everything is evanescent. If you lived with this guy for 65 years to come... he still would be taken from you thru death; his, or your own.
Forget about insecurity and jealousy. If he ever opts to leave, or you decide you can not be with him... THAT will be the time for righteous heartache.