Occupational therapist Christopher Palmares Sy, 35, was granted bail on strict conditions after being accused of having sexual intercourse with a 15-year-old, sexual touching, child grooming and drug supply in February and March.

Police told Parramatta Local Court on Thursday they had evidence Sy asked the girl on WhatsApp if she liked the rose he'd given her on Valentine's Day.

At a meeting the next weekend, the Seaforth man sexually assaulted the girl after instructing her and two others how to take MDMA at a birthday celebration.

Police allege Sy assaulted the girl inside a locked room of a Seaforth home and told those on the outside trying to get in that it was OK.

"There's a strong prosecution case," police prosecutor John Fraser said.

Sy allegedly met the girl while he was volunteering as a taekwondo instructor and picked her up from her house on at least one occasion.

He's accused of sexually assaulting the 15-year-old on another occasion at Freshwater on March 9 and grabbing the girl's breasts at Seaforth six days later.

But his lawyer said it was a "he said, she said" case and there were good prospects of acquittal on most charges.

"A custodial sentence is not a foregone conclusion or even likely," Michael Adamo said.

Magistrate Rodney Brender granted Sy bail on "very strict conditions" after hearing concerns his seven employees could lose their jobs if he remained in custody.

Delays and more arduous prison conditions due to the coronavirus pandemic were also factors, Mr Brender said.

Sy can't leave home except to attend court, medical or legal appointments and to shop for essential items between 8am and 6pm.

He must only use one smartphone and can't access the internet any other way.

"He's not going to be going anywhere much," Mr Brender said.

"Hopefully those people won't lose their jobs."

Sy's case is due to be mentioned before Manly Local Court on June 11.

Australian Associated Press