Tossed in cooperative handjob because I feel this still applies to the spirit of the tag as its 2 people giving a handjob to one person. Its just the one person has 2 dicks instead of 1.
I have a hunch these are their real forms, and what we see is just their acid-induced hallucinations, as evidenced by J.G. Quintel's short form "Two in the AM/PM". Yes, even Benson takes the stuff.