Charlie Territt, 31, from South Bermondsey, was formerly employed as a Higher Level Teaching Assistant at Streatham Wells Primary School.
He is charged with engaging in sexual communication with a child, causing or inciting a child under 13 to engage in sexual activity, and causing a child to watch a sexual act.
Territt pleaded not guilty to the three charges during a brief hearing at Inner London Crown Court on Tuesday, April 1.
The court heard the charges relate to allegations that Territt engaged in a sexual conversation with a child online last year.
Judge Benedict Kelleher set a provisional trial date in February next year.
