Watery, sticky discharge after intercourse is often just a normal mix of vaginal lubrication, arousal fluid and leftover semen, especially when it is clear to whitish and does not have a strong smell. On its own, this usually isn't something serious.
Next Steps
Watch the color and smell, and notice if itching, burning or pelvic discomfort develop over the next couple of days. Breathable cotton underwear and avoiding scented soaps near the area can help.
Health Tips
If it turns yellow or green, smells unusual, or you develop itching or pain, please see a gynaecologist for an exam and, if needed, a vaginal swab test.