Possible child molestation

I am concerned about my 5 yr old Grandson (he will be 6 early Oct). He has approached his 4 yr female cousin on several occasions with what I feel is unappropriate behavior for a 5 - 6 yr old. I will list all the episodes I am aware of from last Christmas to just a week ago.
1. Wanted her take her panties off and sit on his face (this was lat Christmas)
2. Asked her to stick her fingers into her privates and then smell them (this was 3 months ago)
3. Tried to stick a glow stick into her panties (this was a month ago)
4. Laid on the floor and wanted her to lay on top of her
5. Went into the bathroom with her even when she did not want him to...she said he wanted to pull her panties up
6. Was on the floor with his hand down his pants and his arm on her (the last three were on a family vacation last week, all within a 3-day period)
7. He is constantly playing with himself anywhere, anytime.

This just does not seem right...please advise.

Thank you

[Kevin Kennedy, Ph.D.]

His behavior does warrant concern. It does not automatically indicate that he has been mistretade, though he may have been. It certainly indicates some form of overstimulation at the very least. An evaluation by a pediatric mental health clinician would be prudent, as well as very close supervision.