The tag implication #68285 penis_in_own_ass -> autopenetration is pending approval.

Reason: A character penetrating themselves with their own penis is a form of penetration. penis_in_own_vagina already implies this tag.

Edit: Would you prefer that these be grouped under anal_autopenetration and vaginal_autopenetration? That may be more intuitive for people familiar with how penetration is structured, making the current tags aliases.