Depends on how empty and clean the tubes are before they get busy.
If the paramour is a popular lad and has multiple callers (or just a frequent self-pleasure constitutional), the operating environment may not be a sterile field free from DNA.
It’s interesting from a biology perspective, but still good advice to give those teenagers who spend their weekends going at it until they can’t pronounce their own names.
Depends on how empty and clean the tubes are before they get busy.
If the paramour is a popular lad and has multiple callers (or just a frequent self-pleasure constitutional), the operating environment may not be a sterile field free from DNA.
It’s interesting from a biology perspective, but still good advice to give those teenagers who spend their weekends going at it until they can’t pronounce their own names.