Well if it doesn't bother you then enjoy it, however if you don't think of him in "that way" then tell him to please not do that.
What if you and a guy are talking and he suddenly kisses you?
Guys shouldn't kiss a girl out of the clear blue sky, that makes her feel uncomfortable .
I will ask him to stop.
I had been talking to a guy and he kissed me but I liked him, that my friends, was pretty startling.