TRACON controller reported aircraft conflicted with a towered airport's airspace.

Narrative:

Aircraft X advised me that he would be flying VFR at a low altitude. He appeared to be following a typical flight path used by VFR aircraft in the area. The aircraft cut through the northern tip of [two airport's] airspace; which too is a common flight path and a common practice. As the aircraft neared [a visual waypoint]; one of the airport's tower controllers called my line to advise that one of their aircraft who was primary only had aircraft X in sight. Controllers typically observe VFR fly through this northern tip of [their] airspace at low altitude many times a day; every day; without point outs. As this was no different than typical operations in the facility; I did not perceive that there was a problem; until the controller in charge notified me that tower had called to report an airspace violation. In the future I will either instruct VFR aircraft to avoid this small section of airspace; or I will point out the aircraft to the appropriate tower before the aircraft enters the airspace.

Original NASA ASRS Text

Title: TRACON controller reported aircraft conflicted with a towered airport's airspace.

Narrative: Aircraft X advised me that he would be flying VFR at a low altitude. He appeared to be following a typical flight path used by VFR aircraft in the area. The aircraft cut through the northern tip of [two airport's] airspace; which too is a common flight path and a common practice. As the aircraft neared [a visual waypoint]; one of the airport's tower controllers called my line to advise that one of their aircraft who was primary only had Aircraft X in sight. Controllers typically observe VFR fly through this northern tip of [their] airspace at low altitude many times a day; every day; without point outs. As this was no different than typical operations in the facility; I did not perceive that there was a problem; until the CIC notified me that Tower had called to report an airspace violation. In the future I will either instruct VFR aircraft to avoid this small section of airspace; or I will point out the aircraft to the appropriate tower before the aircraft enters the airspace.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1764766
Time
Date	202010
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.TRACON
State Reference	US
Aircraft 1
Make Model Name	Small Aircraft
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	None VFR Route
Flight Plan	VFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Experience	Air Traffic Control Time Certified In Pos 1 (yrs) 6.5
Events
Anomaly	ATC Issue All Types Airspace Violation All Types Conflict Airborne Conflict Deviation - Procedural Published Material / Policy