If you really love him then just say it but remember that love is a strong word.
Also you could show or tell them. If you are in love you will know it!
Although Kyon and Nagato share a close friendship, Kyon is never shown to "love" Nagato. He is mainly paired up with Haruhi.
Tel him u luv him and ask him if he luvz u
Sonic the Hedgehog will kiss her in the new sega movie coming out