is it the man's out to check the woman who trying to come on to him or being too flirty

hi lady,I'll talk to someone at work. but he always allow this girl to play in his hair and rub his shoulder he even took her home one time and share his weed with her well today she came over here to talk to me not about him just to have a general conversation so when I told him about it he want to say to me I'm fake I shouldn't have an issue with her that's when I said I don't have an issue with her. I have an issue with you due to the fact that you will not check her or tell her that does not cool to touch on you like that. he stated he has told her this before. but really she always doing this so how can I believe he really told her