A longtime track and field coach charged with inappropriately touching a student-athlete at a meet in Toms River last month touched the 15-year-old’s buttocks as she stood in line to get a sticker to participate in the event, according to authorities. Thomas Downes, 61, of Jersey City, was charged with endangering the welfare of a child and criminal sexual contact following the incident at the John Bennet Athletic Bubble on Feb. 12. The 15-year-old girl was not a member of the team Downes was coaching, according to an affidavit of probable cause filed in support of the charges. The girl told i…