Ah ha! Gel based ink. Perfect. All is not lost, but it will take a little fine detail effort on your part. Here’s the run-down:

1. blot, don’t rub.

2. put a towel UNDER the stain, so like down the pant leg.

3. apply some rubbing alcohol (isopropyl) with a cotton swab; you should see the stain break up and maybe get on the towel, so use a junk towel.

4. rinse with COOL water.

5. pre-treat with stain remover or liquid detergent.

6. wash in warmest water that garment will allow.

7. CHECK. FOR. THE. STAIN. Before you put your pants in the dryer.

8. GO BACK AND CHECK AGAIN.

9. Still there? Repeat.

10. Not there? Air dry and CHECK AGAIN FOR THE STAIN.

11. Still there? Repeat.

12. Gone? Voila!